diff --git a/osu.Game.Rulesets.Karaoke.Tests/Beatmaps/TestElementId.cs b/osu.Game.Rulesets.Karaoke.Tests/Beatmaps/TestElementId.cs
index 2c80e63f9..e79d8c312 100644
--- a/osu.Game.Rulesets.Karaoke.Tests/Beatmaps/TestElementId.cs
+++ b/osu.Game.Rulesets.Karaoke.Tests/Beatmaps/TestElementId.cs
@@ -35,11 +35,17 @@ public void TestCreateElementId(string id, bool created)
     {
         if (created)
         {
-            Assert.DoesNotThrow(() => new ElementId(id));
+            Assert.DoesNotThrow(() =>
+            {
+                var _ = new ElementId(id);
+            });
         }
         else
         {
-            Assert.Throws<ArgumentException>(() => new ElementId(id));
+            Assert.Throws<ArgumentException>(() =>
+            {
+                var _ = new ElementId(id);
+            });
         }
     }
 
diff --git a/osu.Game.Rulesets.Karaoke.Tests/Editor/TestSceneSetupScreen.cs b/osu.Game.Rulesets.Karaoke.Tests/Editor/TestSceneSetupScreen.cs
index e0573f5b2..8561c7b7f 100644
--- a/osu.Game.Rulesets.Karaoke.Tests/Editor/TestSceneSetupScreen.cs
+++ b/osu.Game.Rulesets.Karaoke.Tests/Editor/TestSceneSetupScreen.cs
@@ -18,22 +18,17 @@ public partial class TestSceneSetupScreen : EditorClockTestScene
 {
     [Cached(typeof(EditorBeatmap))]
     [Cached(typeof(IBeatSnapProvider))]
-    private readonly EditorBeatmap editorBeatmap;
+    private readonly EditorBeatmap editorBeatmap = new(new KaraokeBeatmap
+    {
+        BeatmapInfo =
+        {
+            Ruleset = new KaraokeRuleset().RulesetInfo,
+        },
+    });
 
     [Cached]
     private readonly OverlayColourProvider colourProvider = new(OverlayColourScheme.Blue);
 
-    public TestSceneSetupScreen()
-    {
-        editorBeatmap = new EditorBeatmap(new KaraokeBeatmap
-        {
-            BeatmapInfo =
-            {
-                Ruleset = new KaraokeRuleset().RulesetInfo,
-            },
-        });
-    }
-
     [Test]
     public void TestKaraoke() => runForRuleset(new KaraokeRuleset().RulesetInfo);
 
diff --git a/osu.Game.Rulesets.Karaoke.Tests/Replays/TestSceneAutoGenerationBySinger.cs b/osu.Game.Rulesets.Karaoke.Tests/Replays/TestSceneAutoGenerationBySinger.cs
index abfb7d49f..7d45607b0 100644
--- a/osu.Game.Rulesets.Karaoke.Tests/Replays/TestSceneAutoGenerationBySinger.cs
+++ b/osu.Game.Rulesets.Karaoke.Tests/Replays/TestSceneAutoGenerationBySinger.cs
@@ -56,10 +56,13 @@ private static IReadOnlyList<TestKaraokeReplayFrame> getCompareResultFromName(st
 
     private struct TestKaraokeReplayFrame
     {
+        [JsonProperty]
         public double Time { get; set; }
 
+        [JsonProperty]
         public float Pitch { get; set; }
 
+        [JsonProperty]
         public bool Sound { get; set; }
     }
 }
diff --git a/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/CaretPosition/Algorithms/BaseCaretPositionAlgorithmTest.cs b/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/CaretPosition/Algorithms/BaseCaretPositionAlgorithmTest.cs
index 37af52bb0..0d37d92ed 100644
--- a/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/CaretPosition/Algorithms/BaseCaretPositionAlgorithmTest.cs
+++ b/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/CaretPosition/Algorithms/BaseCaretPositionAlgorithmTest.cs
@@ -106,15 +106,17 @@ protected Lyric[] GetLyricsByMethodName(string methodName)
 
     private static PropertyInfo? getMethod(Type type, string methodName)
     {
-        var theMethod = type.GetProperty(methodName, BindingFlags.NonPublic | BindingFlags.Static);
+        Type? targetType = type;
 
-        if (theMethod != null)
-            return theMethod;
+        while (targetType != null)
+        {
+            var theMethod = targetType.GetProperty(methodName, BindingFlags.NonPublic | BindingFlags.Static);
+            if (theMethod != null)
+                return theMethod;
 
-        var baseType = type.BaseType;
-        if (baseType == null)
-            return null;
+            targetType = targetType.BaseType;
+        }
 
-        return getMethod(baseType, methodName);
+        return null;
     }
 }
diff --git a/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/Components/TestScenePreviewKaraokeSpriteText.cs b/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/Components/TestScenePreviewKaraokeSpriteText.cs
index 6ce3c7855..16923d804 100644
--- a/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/Components/TestScenePreviewKaraokeSpriteText.cs
+++ b/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Beatmap/Lyrics/Components/TestScenePreviewKaraokeSpriteText.cs
@@ -27,18 +27,13 @@ public partial class TestScenePreviewKaraokeSpriteText : OsuTestScene
 
     private Action? updateAction;
 
-    private readonly Lyric lyric;
-
-    public TestScenePreviewKaraokeSpriteText()
+    private readonly Lyric lyric = new()
     {
-        lyric = new Lyric
-        {
-            Text = "カラオケ",
-            TimeTags = TestCaseTagHelper.ParseTimeTags(new[] { "[0,start]:1000", "[1,start]:2000", "[2,start]:3000", "[3,start]:4000", "[3,end]:5000" }),
-            RubyTags = TestCaseTagHelper.ParseRubyTags(new[] { "[0]:か", "[1]:ら", "[2]:お", "[3]:け" }),
-            RomajiTags = TestCaseTagHelper.ParseRomajiTags(new[] { "[0]:ka", "[1]:ra", "[2]:o", "[3]:ke" }),
-        };
-    }
+        Text = "カラオケ",
+        TimeTags = TestCaseTagHelper.ParseTimeTags(new[] { "[0,start]:1000", "[1,start]:2000", "[2,start]:3000", "[3,start]:4000", "[3,end]:5000" }),
+        RubyTags = TestCaseTagHelper.ParseRubyTags(new[] { "[0]:か", "[1]:ら", "[2]:お", "[3]:け" }),
+        RomajiTags = TestCaseTagHelper.ParseRomajiTags(new[] { "[0]:ka", "[1]:ra", "[2]:o", "[3]:ke" }),
+    };
 
     protected override void Update()
     {
diff --git a/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Import/TestSceneLyricImporter.cs b/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Import/TestSceneLyricImporter.cs
index e182d3d87..59b0d42d2 100644
--- a/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Import/TestSceneLyricImporter.cs
+++ b/osu.Game.Rulesets.Karaoke.Tests/Screens/Edit/Import/TestSceneLyricImporter.cs
@@ -25,7 +25,7 @@ public partial class TestSceneLyricImporter : ScreenTestScene<TestSceneLyricImpo
     private readonly OverlayColourProvider overlayColourProvider = new(OverlayColourScheme.Blue);
 
     [Cached]
-    private readonly KaraokeRulesetLyricEditorConfigManager lyricEditorConfigManager;
+    private readonly KaraokeRulesetLyricEditorConfigManager lyricEditorConfigManager = new();
 
     protected override Container<Drawable> Content { get; } = new Container { RelativeSizeAxes = Axes.Both };
 
@@ -37,11 +37,6 @@ protected override TestLyricImporter CreateScreen()
 
     private DialogOverlay dialogOverlay = null!;
 
-    public TestSceneLyricImporter()
-    {
-        lyricEditorConfigManager = new KaraokeRulesetLyricEditorConfigManager();
-    }
-
     [BackgroundDependencyLoader]
     private void load()
     {
diff --git a/osu.Game.Rulesets.Karaoke.Tests/Stages/Classic/ClassicStageInfoTest.cs b/osu.Game.Rulesets.Karaoke.Tests/Stages/Classic/ClassicStageInfoTest.cs
deleted file mode 100644
index 7e8d885ca..000000000
--- a/osu.Game.Rulesets.Karaoke.Tests/Stages/Classic/ClassicStageInfoTest.cs
+++ /dev/null
@@ -1,11 +0,0 @@
-// Copyright (c) andy840119 <andy840119@gmail.com>. Licensed under the GPL Licence.
-// See the LICENCE file in the repository root for full licence text.
-
-namespace osu.Game.Rulesets.Karaoke.Tests.Stages.Classic;
-
-public class ClassicStageInfoTest
-{
-    #region Stage element
-
-    #endregion
-}
diff --git a/osu.Game.Rulesets.Karaoke.Tests/Utils/ComparableUtilsTest.cs b/osu.Game.Rulesets.Karaoke.Tests/Utils/ComparableUtilsTest.cs
index dbab86816..c657dbb77 100644
--- a/osu.Game.Rulesets.Karaoke.Tests/Utils/ComparableUtilsTest.cs
+++ b/osu.Game.Rulesets.Karaoke.Tests/Utils/ComparableUtilsTest.cs
@@ -50,10 +50,13 @@ public void TestCompareByProperty(string leftObjectProperty, string rightObjectP
 
     private class TestObject
     {
-        public int A { get; set; } = 0;
+        [JsonProperty]
+        public int A { get; set; }
 
-        public double B { get; set; } = 0;
+        [JsonProperty]
+        public double B { get; set; }
 
+        [JsonProperty]
         public string C { get; set; } = string.Empty;
     }
 }
diff --git a/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeJsonBeatmapDecoder.cs b/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeJsonBeatmapDecoder.cs
index 52c572a31..4f43fe52d 100644
--- a/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeJsonBeatmapDecoder.cs
+++ b/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeJsonBeatmapDecoder.cs
@@ -48,12 +48,9 @@ protected override IList<JsonProperty> CreateProperties(Type type, MemberSeriali
         {
             var props = base.CreateProperties(type, memberSerialization);
 
-            if (type == typeof(BeatmapInfo))
-            {
-                return props.Where(p => p.PropertyName != "ruleset_id").ToList();
-            }
-
-            return props;
+            return type == typeof(BeatmapInfo)
+                ? props.Where(p => p.PropertyName != "ruleset_id").ToList()
+                : props;
         }
     }
 }
diff --git a/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeLegacyBeatmapEncoder.cs b/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeLegacyBeatmapEncoder.cs
index 0605d9694..c9277f66e 100644
--- a/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeLegacyBeatmapEncoder.cs
+++ b/osu.Game.Rulesets.Karaoke/Beatmaps/Formats/KaraokeLegacyBeatmapEncoder.cs
@@ -52,11 +52,9 @@ private IEnumerable<string> encodeNote(Beatmap output)
         // Convert single note
         static string convertNote(Note note)
         {
-            if (!note.Display)
-                return "-";
-
-            // TODO : Fill if customize ruby and percentage
-            return convertTone(note.Tone);
+            return !note.Display
+                ? "-"
+                : convertTone(note.Tone);
 
             // Convert tone to string
             static string convertTone(Tone tone) => tone.Scale + (tone.Half ? "#" : string.Empty);
diff --git a/osu.Game.Rulesets.Karaoke/Beatmaps/KaraokeBeatmapExtension.cs b/osu.Game.Rulesets.Karaoke/Beatmaps/KaraokeBeatmapExtension.cs
index f17ae952f..c581c44aa 100644
--- a/osu.Game.Rulesets.Karaoke/Beatmaps/KaraokeBeatmapExtension.cs
+++ b/osu.Game.Rulesets.Karaoke/Beatmaps/KaraokeBeatmapExtension.cs
@@ -12,14 +12,9 @@ public static class KaraokeBeatmapExtension
 {
     public static bool IsScorable(this IBeatmap beatmap)
     {
-        if (beatmap is not KaraokeBeatmap karaokeBeatmap)
-        {
-            // we should throw invalidate exception here but it will cause test case failed.
-            // because beatmap in the working beatmap in test case not always be karaoke beatmap class.
-            return false;
-        }
-
-        return karaokeBeatmap.Scorable;
+        // we should throw invalidate exception here but it will cause test case failed.
+        // because beatmap in the working beatmap in test case not always be karaoke beatmap class.
+        return beatmap is KaraokeBeatmap karaokeBeatmap && karaokeBeatmap.Scorable;
     }
 
     public static IList<CultureInfo> AvailableTranslates(this IBeatmap beatmap) => (beatmap as KaraokeBeatmap)?.AvailableTranslates ?? new List<CultureInfo>();
diff --git a/osu.Game.Rulesets.Karaoke/Difficulty/KaraokeDifficultyCalculator.cs b/osu.Game.Rulesets.Karaoke/Difficulty/KaraokeDifficultyCalculator.cs
index 7a12863cf..f620409f7 100644
--- a/osu.Game.Rulesets.Karaoke/Difficulty/KaraokeDifficultyCalculator.cs
+++ b/osu.Game.Rulesets.Karaoke/Difficulty/KaraokeDifficultyCalculator.cs
@@ -79,16 +79,11 @@ protected override IEnumerable<DifficultyHitObject> CreateDifficultyHitObjects(I
 
     private int getHitWindow300(Mod[] mods)
     {
-        if (isForCurrentRuleset)
-        {
-            double od = Math.Min(10.0, Math.Max(0, 10.0 - originalOverallDifficulty));
-            return applyModAdjustments(34 + 3 * od, mods);
-        }
-
-        if (Math.Round(originalOverallDifficulty) > 4)
-            return applyModAdjustments(34, mods);
+        if (!isForCurrentRuleset)
+            return applyModAdjustments(Math.Round(originalOverallDifficulty) > 4 ? 34 : 47, mods);
 
-        return applyModAdjustments(47, mods);
+        double od = Math.Min(10.0, Math.Max(0, 10.0 - originalOverallDifficulty));
+        return applyModAdjustments(34 + 3 * od, mods);
 
         static int applyModAdjustments(double value, Mod[] mods)
         {
diff --git a/osu.Game.Rulesets.Karaoke/Edit/Checks/CheckBeatmapClassicStageInfo.cs b/osu.Game.Rulesets.Karaoke/Edit/Checks/CheckBeatmapClassicStageInfo.cs
index 9668b27cd..59fffaa3a 100644
--- a/osu.Game.Rulesets.Karaoke/Edit/Checks/CheckBeatmapClassicStageInfo.cs
+++ b/osu.Game.Rulesets.Karaoke/Edit/Checks/CheckBeatmapClassicStageInfo.cs
@@ -143,10 +143,6 @@ public IssueTemplateInvalidRowHeight(ICheck check)
         public Issue Create() => new(this);
     }
 
-    #region stage definition
-
-    #endregion
-
     #region timing info
 
     public class IssueTemplateLessThanTwoTimingPoints : IssueTemplate
diff --git a/osu.Game.Rulesets.Karaoke/Edit/KaraokeHitObjectComposer.cs b/osu.Game.Rulesets.Karaoke/Edit/KaraokeHitObjectComposer.cs
index df9664bf8..604008c9d 100644
--- a/osu.Game.Rulesets.Karaoke/Edit/KaraokeHitObjectComposer.cs
+++ b/osu.Game.Rulesets.Karaoke/Edit/KaraokeHitObjectComposer.cs
@@ -126,7 +126,7 @@ public override SnapResult FindSnappedPositionAndTime(Vector2 screenSpacePositio
             : result;
     }
 
-    protected override DrawableRuleset<KaraokeHitObject> CreateDrawableRuleset(Ruleset ruleset, IBeatmap beatmap, IReadOnlyList<Mod>? mods = null)
+    protected override DrawableRuleset<KaraokeHitObject> CreateDrawableRuleset(Ruleset ruleset, IBeatmap beatmap, IReadOnlyList<Mod> mods)
     {
         drawableRuleset = new DrawableKaraokeEditorRuleset(ruleset, beatmap, mods);
 
diff --git a/osu.Game.Rulesets.Karaoke/Edit/Setup/Components/SingerDisplay.cs b/osu.Game.Rulesets.Karaoke/Edit/Setup/Components/SingerDisplay.cs
index 73d621667..1f205ede5 100644
--- a/osu.Game.Rulesets.Karaoke/Edit/Setup/Components/SingerDisplay.cs
+++ b/osu.Game.Rulesets.Karaoke/Edit/Setup/Components/SingerDisplay.cs
@@ -8,7 +8,6 @@
 using osu.Framework.Graphics.Containers;
 using osu.Framework.Graphics.Cursor;
 using osu.Framework.Graphics.UserInterface;
-using osu.Game.Graphics;
 using osu.Game.Graphics.Containers;
 using osu.Game.Graphics.Sprites;
 using osu.Game.Graphics.UserInterface;
@@ -79,9 +78,6 @@ private partial class SingerCircle : OsuClickableContainer, IHasContextMenu, IHa
 
         private readonly DrawableSingerAvatar singerAvatar;
 
-        [Resolved]
-        private OsuColour colours { get; set; } = null!;
-
         public SingerCircle()
         {
             RelativeSizeAxes = Axes.X;
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/CaretPosition/Algorithms/TimeTagCaretPositionAlgorithm.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/CaretPosition/Algorithms/TimeTagCaretPositionAlgorithm.cs
index 272db68cc..fe81965b4 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/CaretPosition/Algorithms/TimeTagCaretPositionAlgorithm.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/CaretPosition/Algorithms/TimeTagCaretPositionAlgorithm.cs
@@ -81,11 +81,8 @@ protected override bool PositionMovable(TimeTagCaretPosition position)
     protected override TimeTagCaretPosition? MoveToFirstLyric()
     {
         var firstLyric = Lyrics.FirstOrDefault(x => x.TimeTags.Any(timeTagMovable));
-        if (firstLyric == null)
-            return null;
-
-        var firstTimeTag = firstLyric.TimeTags.FirstOrDefault(timeTagMovable);
-        if (firstTimeTag == null)
+        var firstTimeTag = firstLyric?.TimeTags.FirstOrDefault(timeTagMovable);
+        if (firstLyric == null || firstTimeTag == null)
             return null;
 
         return CreateCaretPosition(firstLyric, firstTimeTag);
@@ -94,11 +91,8 @@ protected override bool PositionMovable(TimeTagCaretPosition position)
     protected override TimeTagCaretPosition? MoveToLastLyric()
     {
         var lastLyric = Lyrics.LastOrDefault(x => x.TimeTags.Any(timeTagMovable));
-        if (lastLyric == null)
-            return null;
-
-        var lastTimeTag = lastLyric.TimeTags.LastOrDefault(timeTagMovable);
-        if (lastTimeTag == null)
+        var lastTimeTag = lastLyric?.TimeTags.LastOrDefault(timeTagMovable);
+        if (lastLyric == null || lastTimeTag == null)
             return null;
 
         return CreateCaretPosition(lastLyric, lastTimeTag);
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Components/Lyrics/PreviewKaraokeSpriteText.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Components/Lyrics/PreviewKaraokeSpriteText.cs
index 155d4d701..3aa6224a2 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Components/Lyrics/PreviewKaraokeSpriteText.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Components/Lyrics/PreviewKaraokeSpriteText.cs
@@ -26,7 +26,7 @@ public partial class PreviewKaraokeSpriteText : DrawableKaraokeSpriteText<Previe
 
     public Lyric HitObject;
 
-    public Action? SizeChanged = null;
+    public Action? SizeChanged;
 
     private readonly EditorLyricSpriteText spriteText;
 
@@ -136,31 +136,35 @@ public RectangleF GetRectByCharIndicator(int charIndex)
 
     public TimeTag? GetTimeTagByPosition(float position)
     {
+        var hoverIndex = getHoverIndex();
+        if (hoverIndex == null)
+            return null;
+
         // todo: will use better way to get the time-tag
-        var textIndex = getHoverIndex();
-        return HitObject.TimeTags.FirstOrDefault(x => x.Index == textIndex);
+        return HitObject.TimeTags.FirstOrDefault(x => x.Index == hoverIndex);
 
-        TextIndex getHoverIndex()
+        TextIndex? getHoverIndex()
         {
             for (int i = 0; i < Text.Length; i++)
             {
-                if (getTriggerPositionByTimeIndex(new TextIndex(i)) > position)
-                    return new TextIndex(i);
-
-                if (getTriggerPositionByTimeIndex(new TextIndex(i, TextIndex.IndexState.End)) > position)
-                    return new TextIndex(i, TextIndex.IndexState.End);
+                foreach (var indexState in Enum.GetValues<TextIndex.IndexState>())
+                {
+                    var textIndex = new TextIndex(i, indexState);
+                    var triggerRange = getTriggerRange(textIndex);
+                    if (position >= triggerRange.Item1 && position <= triggerRange.Item2)
+                        return textIndex;
+                }
             }
 
-            return new TextIndex(Text.Length - 1, TextIndex.IndexState.End);
+            // hover the last time-tag if exceed the range.
+            return null;
 
-            // todo : might have a better way to call spriteText.GetTimeTagPosition just once.
-            float getTriggerPositionByTimeIndex(TextIndex textIndex)
+            Tuple<float, float> getTriggerRange(TextIndex textIndex)
             {
-                int charIndex = textIndex.Index;
-                float startPosition = spriteText.GetTimeTagPosition(new TextIndex(charIndex)).X;
-                float endPosition = spriteText.GetTimeTagPosition(new TextIndex(charIndex, TextIndex.IndexState.End)).X;
-
-                return TextIndexUtils.GetValueByState(textIndex, () => startPosition + (endPosition - startPosition) / 2, () => endPosition);
+                var rect = spriteText.GetCharacterDrawRectangle(textIndex.Index);
+                return TextIndexUtils.GetValueByState(textIndex,
+                    () => new Tuple<float, float>(rect.Left, rect.Centre.X),
+                    () => new Tuple<float, float>(rect.Centre.X, rect.Right));
             }
         }
     }
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Compose/Toolbar/ToolbarButton.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Compose/Toolbar/ToolbarButton.cs
index cf86183e7..a69468118 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Compose/Toolbar/ToolbarButton.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Compose/Toolbar/ToolbarButton.cs
@@ -5,7 +5,6 @@
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.Textures;
-using osu.Framework.Input;
 using osu.Game.Graphics.Containers;
 using osuTK;
 
@@ -26,9 +25,6 @@ public void SetIcon(Drawable icon)
     [Resolved]
     private TextureStore textures { get; set; } = null!;
 
-    [Resolved]
-    private ReadableKeyCombinationProvider keyCombinationProvider { get; set; } = null!;
-
     public void SetIcon(string texture) =>
         SetIcon(new Sprite
         {
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorClipboard.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorClipboard.cs
index e6332938a..9dd360919 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorClipboard.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorClipboard.cs
@@ -44,9 +44,6 @@ public partial class LyricEditorClipboard : Component, ILyricEditorClipboard
     [Resolved]
     private ITimeTagModeState timeTagModeState { get; set; } = null!;
 
-    [Resolved]
-    private IEditRomajiModeState editRomajiModeState { get; set; } = null!;
-
     [Resolved]
     private ILyricsChangeHandler? lyricsChangeHandler { get; set; }
 
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorVerifier.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorVerifier.cs
index f003a0504..100015ceb 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorVerifier.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/LyricEditorVerifier.cs
@@ -21,7 +21,7 @@ namespace osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Lyrics;
 public partial class LyricEditorVerifier : EditorVerifier<LyricEditorMode>, ILyricEditorVerifier
 {
     [Resolved]
-    private EditorBeatmap beatmap { get; set; } = null!;
+    private EditorBeatmap editorBeatmap { get; set; } = null!;
 
     private readonly Dictionary<KaraokeHitObject, BindableList<Issue>> hitObjectIssues = new();
 
@@ -65,9 +65,9 @@ protected override void LoadComplete()
         base.LoadComplete();
 
         // need to check is there any lyric added or removed.
-        beatmap.HitObjectAdded += hitObjectAdded;
-        beatmap.HitObjectRemoved += hitObjectRemoved;
-        beatmap.HitObjectUpdated += hitObjectUpdated;
+        editorBeatmap.HitObjectAdded += hitObjectAdded;
+        editorBeatmap.HitObjectRemoved += hitObjectRemoved;
+        editorBeatmap.HitObjectUpdated += hitObjectUpdated;
 
         recalculateIssues();
     }
@@ -80,7 +80,7 @@ private void load(KaraokeRulesetEditCheckerConfigManager? rulesetEditCheckerConf
 
     private void recalculateIssues()
     {
-        var hitObjects = beatmap.HitObjects.OfType<KaraokeHitObject>().ToArray();
+        var hitObjects = editorBeatmap.HitObjects.OfType<KaraokeHitObject>().ToArray();
         var listedHitObjects = hitObjectIssues.Keys.ToArray();
 
         var newHitObjects = hitObjects.Except(listedHitObjects);
@@ -182,9 +182,9 @@ protected override void Dispose(bool isDisposing)
     {
         base.Dispose(isDisposing);
 
-        beatmap.HitObjectAdded -= hitObjectAdded;
-        beatmap.HitObjectRemoved -= hitObjectRemoved;
-        beatmap.HitObjectUpdated -= hitObjectUpdated;
+        editorBeatmap.HitObjectAdded -= hitObjectAdded;
+        editorBeatmap.HitObjectRemoved -= hitObjectRemoved;
+        editorBeatmap.HitObjectUpdated -= hitObjectUpdated;
     }
 }
 
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/LyricEditorAutoGenerateSubsection.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/LyricEditorAutoGenerateSubsection.cs
index 22c7eee24..8d2135754 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/LyricEditorAutoGenerateSubsection.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/LyricEditorAutoGenerateSubsection.cs
@@ -17,7 +17,7 @@ public abstract partial class LyricEditorAutoGenerateSubsection : AutoGenerateSu
 
     protected LyricEditorAutoGenerateSubsection(AutoGenerateType generateType)
     {
-        this.autoGenerateType = generateType;
+        autoGenerateType = generateType;
     }
 
     protected override EditorSectionButton CreateGenerateButton()
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Romaji/RomajiEditSection.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Romaji/RomajiEditSection.cs
index e70646019..dffe4b520 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Romaji/RomajiEditSection.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/Settings/Romaji/RomajiEditSection.cs
@@ -11,7 +11,6 @@
 using osu.Game.Rulesets.Karaoke.Extensions;
 using osu.Game.Rulesets.Karaoke.Objects;
 using osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Lyrics.States.Modes;
-using osu.Game.Screens.Edit;
 
 namespace osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Lyrics.Settings.Romaji;
 
@@ -44,9 +43,6 @@ private partial class RomajiTagsEditor : LyricPropertiesEditor
     {
         private readonly Bindable<RomajiEditPropertyMode> bindableRomajiEditPropertyMode = new();
 
-        [Resolved]
-        private EditorBeatmap beatmap { get; set; } = null!;
-
         public RomajiTagsEditor()
         {
             bindableRomajiEditPropertyMode.BindValueChanged(e =>
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/States/Modes/IHasEditStep.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/States/Modes/IHasEditStep.cs
index 2931161c9..82b5b3185 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/States/Modes/IHasEditStep.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Lyrics/States/Modes/IHasEditStep.cs
@@ -6,11 +6,11 @@
 
 namespace osu.Game.Rulesets.Karaoke.Screens.Edit.Beatmaps.Lyrics.States.Modes;
 
-public interface IHasEditStep<T> where T : Enum
+public interface IHasEditStep<TEditStep> where TEditStep : Enum
 {
-    IBindable<T> BindableEditStep { get; }
+    IBindable<TEditStep> BindableEditStep { get; }
 
-    T EditStep => BindableEditStep.Value;
+    TEditStep EditStep => BindableEditStep.Value;
 
-    void ChangeEditStep(T mode);
+    void ChangeEditStep(TEditStep step);
 }
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Pages/PageScreen.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Pages/PageScreen.cs
index 78fcec632..afaedad43 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Pages/PageScreen.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Pages/PageScreen.cs
@@ -94,14 +94,12 @@ public void Select(Page item)
 
     private partial class FixedSectionsContainer<T> : SectionsContainer<T> where T : Drawable
     {
-        private readonly Container<T> content;
-
         // todo: check what this shit doing.
-        protected override Container<T> Content => content;
+        protected override Container<T> Content { get; }
 
         public FixedSectionsContainer()
         {
-            AddInternal(content = new Container<T>
+            AddInternal(Content = new Container<T>
             {
                 Masking = true,
                 RelativeSizeAxes = Axes.Both,
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerScreen.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerScreen.cs
index 961c71232..989f7be45 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerScreen.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Beatmaps/Singers/SingerScreen.cs
@@ -83,14 +83,12 @@ protected override void PopOut()
 
     private partial class FixedSectionsContainer<T> : SectionsContainer<T> where T : Drawable
     {
-        private readonly Container<T> content;
-
         // todo: check what this shit doing.
-        protected override Container<T> Content => content;
+        protected override Container<T> Content { get; }
 
         public FixedSectionsContainer()
         {
-            AddInternal(content = new Container<T>
+            AddInternal(Content = new Container<T>
             {
                 Masking = true,
                 RelativeSizeAxes = Axes.Both,
diff --git a/osu.Game.Rulesets.Karaoke/Screens/Edit/Import/Lyrics/GenerateRuby/GenerateRubyNavigation.cs b/osu.Game.Rulesets.Karaoke/Screens/Edit/Import/Lyrics/GenerateRuby/GenerateRubyNavigation.cs
index 12042430d..97009fceb 100644
--- a/osu.Game.Rulesets.Karaoke/Screens/Edit/Import/Lyrics/GenerateRuby/GenerateRubyNavigation.cs
+++ b/osu.Game.Rulesets.Karaoke/Screens/Edit/Import/Lyrics/GenerateRuby/GenerateRubyNavigation.cs
@@ -43,8 +43,8 @@ protected override LocalisableString GetNavigationText(NavigationState value) =>
         value switch
         {
             NavigationState.Initial => $"Lazy to typing ruby? Press [{auto_generate_ruby}].",
-            NavigationState.Working => $"Go to next step to generate time-tag.",
-            NavigationState.Done => $"Go to next step to generate time-tag.",
+            NavigationState.Working => "Go to next step to generate time-tag.",
+            NavigationState.Done => "Go to next step to generate time-tag.",
             NavigationState.Error => "Oops, seems cause some error in here.",
             _ => throw new ArgumentOutOfRangeException(nameof(value)),
         };
diff --git a/osu.Game.Rulesets.Karaoke/Utils/CharUtils.cs b/osu.Game.Rulesets.Karaoke/Utils/CharUtils.cs
index b381b9656..31964e4d7 100644
--- a/osu.Game.Rulesets.Karaoke/Utils/CharUtils.cs
+++ b/osu.Game.Rulesets.Karaoke/Utils/CharUtils.cs
@@ -64,17 +64,17 @@ public static bool IsChinese(char c)
     /// <returns></returns>
     public static bool IsLatin(char c)
     {
-        if (c >= 'A' && c <= 'Z')
-            return true;
+        switch (c)
+        {
+            case >= 'A' and <= 'Z':
+            case >= 'a' and <= 'z':
+            // another romanized characters
+            // see: https://www.unicode.org/charts/PDF/U1E00.pdf
+            case >= '\u1E00' and <= '\u1EFF':
+                return true;
 
-        if (c >= 'a' && c <= 'z')
-            return true;
-
-        // another romanized characters
-        // see: https://www.unicode.org/charts/PDF/U1E00.pdf
-        if (c >= '\u1E00' && c <= '\u1EFF')
-            return true;
-
-        return false;
+            default:
+                return false;
+        }
     }
 }
diff --git a/osu.Game.Rulesets.Karaoke/Utils/FontUtils.cs b/osu.Game.Rulesets.Karaoke/Utils/FontUtils.cs
index 98feb8680..589bfa350 100644
--- a/osu.Game.Rulesets.Karaoke/Utils/FontUtils.cs
+++ b/osu.Game.Rulesets.Karaoke/Utils/FontUtils.cs
@@ -17,17 +17,8 @@ public static class FontUtils
     public static float[] DefaultFontSize()
         => new float[] { 8, 9, 10, 11, 12, 14, 16, 18, 20, 22, 24, 26, 28, 36, 48, 72 };
 
-    public static float[] DefaultFontSize(float? minSize = null, float? maxSize = null)
-        => DefaultFontSize().Where(x =>
-        {
-            if (minSize.HasValue && x < minSize.Value)
-                return false;
-
-            if (maxSize.HasValue && x > maxSize.Value)
-                return false;
-
-            return true;
-        }).ToArray();
+    public static float[] DefaultFontSize(float minSize, float maxSize)
+        => DefaultFontSize().Where(x => x >= minSize && x <= maxSize).ToArray();
 
     /// <summary>
     /// For selecting preview size in editor.