diff --git a/packages/frontend/src/components/MkEmojiPicker.section.vue b/packages/frontend/src/components/MkEmojiPicker.section.vue
index 30ad2bcbbfd3..c295ab6bb7cd 100644
--- a/packages/frontend/src/components/MkEmojiPicker.section.vue
+++ b/packages/frontend/src/components/MkEmojiPicker.section.vue
@@ -16,6 +16,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 			:key="emoji"
 			:data-emoji="emoji"
 			class="_button item"
+			:disabled="disabledEmojis?.value.includes(emoji)"
 			@pointerenter="computeButtonTitle"
 			@click="emit('chosen', emoji, $event)"
 		>
@@ -48,6 +49,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 			:key="emoji"
 			:data-emoji="emoji"
 			class="_button item"
+			:disabled="disabledEmojis?.value.includes(emoji)"
 			@pointerenter="computeButtonTitle"
 			@click="emit('chosen', emoji, $event)"
 		>
@@ -67,6 +69,7 @@ import MkEmojiPickerSection from '@/components/MkEmojiPicker.section.vue';
 
 const props = defineProps<{
 	emojis: string[] | Ref<string[]>;
+	disabledEmojis?: Ref<string[]>;
 	initialShown?: boolean;
 	hasChildSection?: boolean;
 	customEmojiTree?: CustomEmojiFolderTree[];
diff --git a/packages/frontend/src/components/MkEmojiPicker.vue b/packages/frontend/src/components/MkEmojiPicker.vue
index 366273118b47..061afa66ac03 100644
--- a/packages/frontend/src/components/MkEmojiPicker.vue
+++ b/packages/frontend/src/components/MkEmojiPicker.vue
@@ -14,6 +14,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 					v-for="emoji in searchResultCustom"
 					:key="emoji.name"
 					class="_button item"
+					:disabled="!canReact(emoji)"
 					:title="emoji.name"
 					tabindex="0"
 					@click="chosen(emoji, $event)"
@@ -39,16 +40,17 @@ SPDX-License-Identifier: AGPL-3.0-only
 			<section v-if="showPinned && (pinned && pinned.length > 0)">
 				<div class="body">
 					<button
-						v-for="emoji in pinned"
-						:key="emoji"
-						:data-emoji="emoji"
+						v-for="emoji in pinnedEmojisDef"
+						:key="getKey(emoji)"
+						:data-emoji="getKey(emoji)"
 						class="_button item"
+						:disabled="!canReact(emoji)"
 						tabindex="0"
 						@pointerenter="computeButtonTitle"
 						@click="chosen(emoji, $event)"
 					>
-						<MkCustomEmoji v-if="emoji[0] === ':'" class="emoji" :name="emoji" :normal="true"/>
-						<MkEmoji v-else class="emoji" :emoji="emoji" :normal="true"/>
+						<MkCustomEmoji v-if="!emoji.hasOwnProperty('char')" class="emoji" :name="getKey(emoji)" :normal="true"/>
+						<MkEmoji v-else class="emoji" :emoji="getKey(emoji)" :normal="true"/>
 					</button>
 				</div>
 			</section>
@@ -57,15 +59,16 @@ SPDX-License-Identifier: AGPL-3.0-only
 				<header class="_acrylic"><i class="ti ti-clock ti-fw"></i> {{ i18n.ts.recentUsed }}</header>
 				<div class="body">
 					<button
-						v-for="emoji in recentlyUsedEmojis"
-						:key="emoji"
+						v-for="emoji in recentlyUsedEmojisDef"
+						:key="getKey(emoji)"
 						class="_button item"
-						:data-emoji="emoji"
+						:disabled="!canReact(emoji)"
+						:data-emoji="getKey(emoji)"
 						@pointerenter="computeButtonTitle"
 						@click="chosen(emoji, $event)"
 					>
-						<MkCustomEmoji v-if="emoji[0] === ':'" class="emoji" :name="emoji" :normal="true"/>
-						<MkEmoji v-else class="emoji" :emoji="emoji" :normal="true"/>
+						<MkCustomEmoji v-if="!emoji.hasOwnProperty('char')" class="emoji" :name="getKey(emoji)" :normal="true"/>
+						<MkEmoji v-else class="emoji" :emoji="getKey(emoji)" :normal="true"/>
 					</button>
 				</div>
 			</section>
@@ -76,7 +79,8 @@ SPDX-License-Identifier: AGPL-3.0-only
 				v-for="child in customEmojiFolderRoot.children"
 				:key="`custom:${child.value}`"
 				:initialShown="false"
-				:emojis="computed(() => customEmojis.filter(e => child.value === '' ? (e.category === 'null' || !e.category) : e.category === child.value).filter(filterAvailable).map(e => `:${e.name}:`))"
+				:emojis="computed(() => customEmojis.filter(e => filterCategory(e, child.value)).map(e => `:${e.name}:`))"
+				:disabledEmojis="computed(() => customEmojis.filter(e => filterCategory(e, child.value)).filter(e => !canReact(e)).map(e => `:${e.name}:`))"
 				:hasChildSection="child.children.length !== 0"
 				:customEmojiTree="child.children"
 				@chosen="chosen"
@@ -104,6 +108,7 @@ import * as Misskey from 'misskey-js';
 import XSection from '@/components/MkEmojiPicker.section.vue';
 import {
 	emojilist,
+	unicodeEmojisMap,
 	emojiCharByCategory,
 	UnicodeEmojiDef,
 	unicodeEmojiCategories as categories,
@@ -146,6 +151,13 @@ const {
 	recentlyUsedEmojis,
 } = defaultStore.reactiveState;
 
+const recentlyUsedEmojisDef = computed(() => {
+	return recentlyUsedEmojis.value.map(getDef);
+});
+const pinnedEmojisDef = computed(() => {
+	return pinned.value?.map(getDef);
+});
+
 const pinned = computed(() => props.pinnedEmojis);
 const size = computed(() => emojiPickerScale.value);
 const width = computed(() => emojiPickerWidth.value);
@@ -337,14 +349,18 @@ watch(q, () => {
 		return matches;
 	};
 
-	searchResultCustom.value = Array.from(searchCustom()).filter(filterAvailable);
+	searchResultCustom.value = Array.from(searchCustom());
 	searchResultUnicode.value = Array.from(searchUnicode());
 });
 
-function filterAvailable(emoji: Misskey.entities.EmojiSimple): boolean {
+function canReact(emoji: Misskey.entities.EmojiSimple | UnicodeEmojiDef): boolean {
 	return !props.targetNote || checkReactionPermissions($i!, props.targetNote, emoji);
 }
 
+function filterCategory(emoji: Misskey.entities.EmojiSimple, category: string): boolean {
+	return category === '' ? (emoji.category === 'null' || !emoji.category) : emoji.category === category;
+}
+
 function focus() {
 	if (!['smartphone', 'tablet'].includes(deviceKind) && !isTouchUsing) {
 		searchEl.value?.focus({
@@ -362,6 +378,14 @@ function getKey(emoji: string | Misskey.entities.EmojiSimple | UnicodeEmojiDef):
 	return typeof emoji === 'string' ? emoji : 'char' in emoji ? emoji.char : `:${emoji.name}:`;
 }
 
+function getDef(emoji: string) {
+	if (emoji.includes(':')) {
+		return customEmojisMap.get(emoji.replace(/:/g, ''))!;
+	} else {
+		return unicodeEmojisMap.get(emoji)!;
+	}
+}
+
 /** @see MkEmojiPicker.section.vue */
 function computeButtonTitle(ev: MouseEvent): void {
 	const elm = ev.target as HTMLElement;
@@ -526,6 +550,18 @@ defineExpose({
 						width: auto;
 						height: auto;
 						min-width: 0;
+
+						&:disabled {
+							cursor: not-allowed;
+							background: linear-gradient(-45deg, transparent 0% 48%, var(--X6) 48% 52%, transparent 52% 100%);
+							opacity: 1;
+
+							> .emoji {
+								filter: grayscale(1);
+								mix-blend-mode: exclusion;
+								opacity: 0.8;
+							}
+						}
 					}
 				}
 			}
@@ -548,6 +584,18 @@ defineExpose({
 						width: auto;
 						height: auto;
 						min-width: 0;
+
+						&:disabled {
+							cursor: not-allowed;
+							background: linear-gradient(-45deg, transparent 0% 48%, var(--X6) 48% 52%, transparent 52% 100%);
+							opacity: 1;
+
+							> .emoji {
+								filter: grayscale(1);
+								mix-blend-mode: exclusion;
+								opacity: 0.8;
+							}
+						}
 					}
 				}
 			}
@@ -663,6 +711,18 @@ defineExpose({
 						box-shadow: inset 0 0.15em 0.3em rgba(27, 31, 35, 0.15);
 					}
 
+					&:disabled {
+						cursor: not-allowed;
+						background: linear-gradient(-45deg, transparent 0% 48%, var(--X6) 48% 52%, transparent 52% 100%);
+						opacity: 1;
+
+						> .emoji {
+							filter: grayscale(1);
+							mix-blend-mode: exclusion;
+							opacity: 0.8;
+						}
+					}
+
 					> .emoji {
 						height: 1.25em;
 						vertical-align: -.25em;
diff --git a/packages/frontend/src/components/MkReactionsViewer.reaction.vue b/packages/frontend/src/components/MkReactionsViewer.reaction.vue
index 0dcd8b0ea25b..bccee5109de9 100644
--- a/packages/frontend/src/components/MkReactionsViewer.reaction.vue
+++ b/packages/frontend/src/components/MkReactionsViewer.reaction.vue
@@ -33,7 +33,8 @@ import { defaultStore } from '@/store.js';
 import { i18n } from '@/i18n.js';
 import * as sound from '@/scripts/sound.js';
 import { checkReactionPermissions } from '@/scripts/check-reaction-permissions.js';
-import { customEmojis } from '@/custom-emojis.js';
+import { customEmojisMap } from '@/custom-emojis.js';
+import { unicodeEmojisMap } from '@/scripts/emojilist.js';
 
 const props = defineProps<{
 	reaction: string;
@@ -50,13 +51,11 @@ const emit = defineEmits<{
 
 const buttonEl = shallowRef<HTMLElement>();
 
-const isCustomEmoji = computed(() => props.reaction.includes(':'));
-const emoji = computed(() => isCustomEmoji.value ? customEmojis.value.find(emoji => emoji.name === props.reaction.replace(/:/g, '').replace(/@\./, '')) : null);
+const emojiName = computed(() => props.reaction.replace(/:/g, '').replace(/@\./, ''));
+const emoji = computed(() => customEmojisMap.get(emojiName.value) ?? unicodeEmojisMap.get(props.reaction));
 
 const canToggle = computed(() => {
-	return !props.reaction.match(/@\w/) && $i
-			&& (emoji.value && checkReactionPermissions($i, props.note, emoji.value))
-			|| !isCustomEmoji.value;
+	return !props.reaction.match(/@\w/) && $i && emoji.value && checkReactionPermissions($i, props.note, emoji.value);
 });
 const canGetInfo = computed(() => !props.reaction.match(/@\w/) && props.reaction.includes(':'));
 
diff --git a/packages/frontend/src/scripts/check-reaction-permissions.ts b/packages/frontend/src/scripts/check-reaction-permissions.ts
index c9d2a5bfc6bf..da704717c127 100644
--- a/packages/frontend/src/scripts/check-reaction-permissions.ts
+++ b/packages/frontend/src/scripts/check-reaction-permissions.ts
@@ -1,6 +1,10 @@
 import * as Misskey from 'misskey-js';
+import { UnicodeEmojiDef } from './emojilist.js';
 
-export function checkReactionPermissions(me: Misskey.entities.MeDetailed, note: Misskey.entities.Note, emoji: Misskey.entities.EmojiSimple): boolean {
+export function checkReactionPermissions(me: Misskey.entities.MeDetailed, note: Misskey.entities.Note, emoji: Misskey.entities.EmojiSimple | UnicodeEmojiDef): boolean {
+  if ('char' in emoji) return true; // UnicodeEmojiDefなら常にリアクション可能
+
+  emoji = emoji as Misskey.entities.EmojiSimple;
   const roleIdsThatCanBeUsedThisEmojiAsReaction = emoji.roleIdsThatCanBeUsedThisEmojiAsReaction ?? [];
   return !(emoji.localOnly && note.user.host !== me.host)
       && !(emoji.isSensitive && (note.reactionAcceptance === 'nonSensitiveOnly' || note.reactionAcceptance === 'nonSensitiveOnlyForLocalLikeOnlyForRemote'))
diff --git a/packages/frontend/src/scripts/emojilist.ts b/packages/frontend/src/scripts/emojilist.ts
index 54d45e025f60..2a6120f3bad6 100644
--- a/packages/frontend/src/scripts/emojilist.ts
+++ b/packages/frontend/src/scripts/emojilist.ts
@@ -20,6 +20,10 @@ export const emojilist: UnicodeEmojiDef[] = _emojilist.map(x => ({
 	category: unicodeEmojiCategories[x[2]],
 }));
 
+export const unicodeEmojisMap = new Map<string, UnicodeEmojiDef>(
+	emojilist.map(x => [x.char, x])
+);
+
 const _indexByChar = new Map<string, number>();
 const _charGroupByCategory = new Map<string, string[]>();
 for (let i = 0; i < emojilist.length; i++) {