diff --git a/packages/frontend/src/components/MkNotifications.vue b/packages/frontend/src/components/MkNotifications.vue
index 177ae0219c..308a077bd9 100644
--- a/packages/frontend/src/components/MkNotifications.vue
+++ b/packages/frontend/src/components/MkNotifications.vue
@@ -103,18 +103,38 @@ defineExpose({
 </script>
 
 <style lang="scss" module>
-.transition_x_move,
-.transition_x_enterActive,
-.transition_x_leaveActive {
-	transition: opacity 0.3s cubic-bezier(0,.5,.5,1), transform 0.3s cubic-bezier(0,.5,.5,1) !important;
+.transition_x_move {
+	transition: transform 0.7s cubic-bezier(0.23, 1, 0.32, 1);
 }
-.transition_x_enterFrom,
+
+.transition_x_enterActive {
+	transition: transform 0.7s cubic-bezier(0.23, 1, 0.32, 1), opacity 0.7s cubic-bezier(0.23, 1, 0.32, 1);
+
+	&.item,
+	.item {
+		/* Skip Note Rendering有効時、TransitionGroupで通知を追加するときに一瞬がくっとなる問題を抑制する */
+		content-visibility: visible !important;
+	}
+}
+
+.transition_x_leaveActive {
+	transition: height 0.2s cubic-bezier(0,.5,.5,1), opacity 0.2s cubic-bezier(0,.5,.5,1);
+}
+
+.transition_x_enterFrom {
+	opacity: 0;
+	transform: translateY(max(-64px, -100%));
+}
+
+@supports (interpolate-size: allow-keywords) {
+	.transition_x_enterFrom {
+		interpolate-size: allow-keywords; // heightのtransitionを動作させるために必要
+		height: 0;
+	}
+}
+
 .transition_x_leaveTo {
 	opacity: 0;
-	transform: translateY(-50%);
-}
-.transition_x_leaveActive {
-	position: absolute;
 }
 
 .notifications {
diff --git a/packages/frontend/src/components/MkTimeline.vue b/packages/frontend/src/components/MkTimeline.vue
index bbf1a03c32..e2c261787b 100644
--- a/packages/frontend/src/components/MkTimeline.vue
+++ b/packages/frontend/src/components/MkTimeline.vue
@@ -21,7 +21,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 				:leaveActiveClass="$style.transition_x_leaveActive"
 				:enterFromClass="$style.transition_x_enterFrom"
 				:leaveToClass="$style.transition_x_leaveTo"
-				:moveClass=" $style.transition_x_move"
+				:moveClass="$style.transition_x_move"
 				tag="div"
 			>
 				<template v-for="(note, i) in notes" :key="note.id">
@@ -305,18 +305,38 @@ defineExpose({
 </script>
 
 <style lang="scss" module>
-.transition_x_move,
-.transition_x_enterActive,
-.transition_x_leaveActive {
-	transition: opacity 0.3s cubic-bezier(0,.5,.5,1), transform 0.3s cubic-bezier(0,.5,.5,1) !important;
+.transition_x_move {
+	transition: transform 0.7s cubic-bezier(0.23, 1, 0.32, 1);
 }
-.transition_x_enterFrom,
+
+.transition_x_enterActive {
+	transition: transform 0.7s cubic-bezier(0.23, 1, 0.32, 1), opacity 0.7s cubic-bezier(0.23, 1, 0.32, 1);
+
+	&.note,
+	.note {
+		/* Skip Note Rendering有効時、TransitionGroupでnoteを追加するときに一瞬がくっとなる問題を抑制する */
+		content-visibility: visible !important;
+	}
+}
+
+.transition_x_leaveActive {
+	transition: height 0.2s cubic-bezier(0,.5,.5,1), opacity 0.2s cubic-bezier(0,.5,.5,1);
+}
+
+.transition_x_enterFrom {
+	opacity: 0;
+	transform: translateY(max(-64px, -100%));
+}
+
+@supports (interpolate-size: allow-keywords) {
+	.transition_x_leaveTo {
+		interpolate-size: allow-keywords; // heightのtransitionを動作させるために必要
+		height: 0;
+	}
+}
+
 .transition_x_leaveTo {
 	opacity: 0;
-	transform: translateY(-50%);
-}
-.transition_x_leaveActive {
-	position: absolute;
 }
 
 .reverse {