fix(startup): async dictionary loading and unblock first tokenization

- move JLPT/frequency dictionary init off sync fs APIs and add cooperative yielding during entry processing

- decouple first tokenization from full warmup by gating only on Yomitan readiness while MeCab/dictionary warmups continue in parallel

- update mpv pause-until-ready OSD copy to tokenization-focused wording and refresh gate regression assertions

plugin/subminer/process.lua

@@ -3,6 +3,8 @@ local M = {}
 local OVERLAY_START_RETRY_DELAY_SECONDS = 0.2
 local OVERLAY_START_MAX_ATTEMPTS = 6
 local AUTO_PLAY_READY_TIMEOUT_SECONDS = 15
+local AUTO_PLAY_READY_LOADING_OSD = "Loading subtitle tokenization..."
+local AUTO_PLAY_READY_READY_OSD = "Subtitle tokenization ready"
 
 function M.create(ctx)
 	local mp = ctx.mp
@@ -90,7 +92,7 @@ function M.create(ctx)
 		end
 		disarm_auto_play_ready_gate()
 		mp.set_property_native("pause", false)
-		show_osd("Subtitle annotations loaded")
+		show_osd(AUTO_PLAY_READY_READY_OSD)
 		subminer_log("info", "process", "Resuming playback after startup gate: " .. tostring(reason or "ready"))
 	end
 
@@ -101,11 +103,11 @@ function M.create(ctx)
 		end
 		state.auto_play_ready_gate_armed = true
 		mp.set_property_native("pause", true)
-		show_osd("Loading subtitle annotations...")
+		show_osd(AUTO_PLAY_READY_LOADING_OSD)
 		if type(mp.add_periodic_timer) == "function" then
 			state.auto_play_ready_osd_timer = mp.add_periodic_timer(2.5, function()
 				if state.auto_play_ready_gate_armed then
-					show_osd("Loading subtitle annotations...")
+					show_osd(AUTO_PLAY_READY_LOADING_OSD)
 				end
 			end)
 		end

scripts/test-plugin-start-gate.lua

@@ -551,7 +551,7 @@ do
 		"autoplay-ready script message should resume mpv playback"
 	)
 	assert_true(
-		has_osd_message(recorded.osd, "SubMiner: Loading subtitle annotations..."),
+		has_osd_message(recorded.osd, "SubMiner: Loading subtitle tokenization..."),
 		"pause-until-ready auto-start should show loading OSD message"
 	)
 	assert_true(
@@ -559,7 +559,7 @@ do
 		"pause-until-ready auto-start should avoid replacing loading OSD with generic starting OSD"
 	)
 	assert_true(
-		has_osd_message(recorded.osd, "SubMiner: Subtitle annotations loaded"),
+		has_osd_message(recorded.osd, "SubMiner: Subtitle tokenization ready"),
 		"autoplay-ready should show loaded OSD message"
 	)
 	assert_true(

src/core/services/frequency-dictionary.test.ts

@@ -129,3 +129,39 @@ test('createFrequencyDictionaryLookup parses composite displayValue by primary r
   assert.equal(lookup('鍛える'), 3272);
   assert.equal(lookup('高み'), 9933);
 });
+
+test('createFrequencyDictionaryLookup does not require synchronous fs APIs', async () => {
+  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-frequency-dict-'));
+  const bankPath = path.join(tempDir, 'term_meta_bank_1.json');
+  fs.writeFileSync(bankPath, JSON.stringify([['猫', 1, { frequency: { displayValue: 42 } }]]));
+
+  const readFileSync = fs.readFileSync;
+  const readdirSync = fs.readdirSync;
+  const statSync = fs.statSync;
+  const existsSync = fs.existsSync;
+  (fs as unknown as Record<string, unknown>).readFileSync = () => {
+    throw new Error('sync read disabled');
+  };
+  (fs as unknown as Record<string, unknown>).readdirSync = () => {
+    throw new Error('sync readdir disabled');
+  };
+  (fs as unknown as Record<string, unknown>).statSync = () => {
+    throw new Error('sync stat disabled');
+  };
+  (fs as unknown as Record<string, unknown>).existsSync = () => {
+    throw new Error('sync exists disabled');
+  };
+
+  try {
+    const lookup = await createFrequencyDictionaryLookup({
+      searchPaths: [tempDir],
+      log: () => undefined,
+    });
+    assert.equal(lookup('猫'), 42);
+  } finally {
+    (fs as unknown as Record<string, unknown>).readFileSync = readFileSync;
+    (fs as unknown as Record<string, unknown>).readdirSync = readdirSync;
+    (fs as unknown as Record<string, unknown>).statSync = statSync;
+    (fs as unknown as Record<string, unknown>).existsSync = existsSync;
+  }
+});

src/core/services/frequency-dictionary.ts

@@ -1,4 +1,4 @@
-import * as fs from 'node:fs';
+import * as fs from 'node:fs/promises';
 import * as path from 'node:path';
 
 export interface FrequencyDictionaryLookupOptions {
@@ -13,6 +13,17 @@ interface FrequencyDictionaryEntry {
 
 const FREQUENCY_BANK_FILE_GLOB = /^term_meta_bank_.*\.json$/;
 const NOOP_LOOKUP = (): null => null;
+const ENTRY_YIELD_INTERVAL = 5000;
+
+function isErrorCode(error: unknown, code: string): boolean {
+  return Boolean(error && typeof error === 'object' && (error as { code?: unknown }).code === code);
+}
+
+async function yieldToEventLoop(): Promise<void> {
+  await new Promise<void>((resolve) => {
+    setImmediate(resolve);
+  });
+}
 
 function normalizeFrequencyTerm(value: string): string {
   return value.trim().toLowerCase();
@@ -93,16 +104,22 @@ function asFrequencyDictionaryEntry(entry: unknown): FrequencyDictionaryEntry |
   };
 }
 
-function addEntriesToMap(
+async function addEntriesToMap(
   rawEntries: unknown,
   terms: Map<string, number>,
-): { duplicateCount: number } {
+): Promise<{ duplicateCount: number }> {
   if (!Array.isArray(rawEntries)) {
     return { duplicateCount: 0 };
   }
 
   let duplicateCount = 0;
+  let processedCount = 0;
   for (const rawEntry of rawEntries) {
+    processedCount += 1;
+    if (processedCount % ENTRY_YIELD_INTERVAL === 0) {
+      await yieldToEventLoop();
+    }
+
     const entry = asFrequencyDictionaryEntry(rawEntry);
     if (!entry) {
       continue;
@@ -119,15 +136,15 @@ function addEntriesToMap(
   return { duplicateCount };
 }
 
-function collectDictionaryFromPath(
+async function collectDictionaryFromPath(
   dictionaryPath: string,
   log: (message: string) => void,
-): Map<string, number> {
+): Promise<Map<string, number>> {
   const terms = new Map<string, number>();
 
   let fileNames: string[];
   try {
-    fileNames = fs.readdirSync(dictionaryPath);
+    fileNames = await fs.readdir(dictionaryPath);
   } catch (error) {
     log(`Failed to read frequency dictionary directory ${dictionaryPath}: ${String(error)}`);
     return terms;
@@ -143,7 +160,7 @@ function collectDictionaryFromPath(
     const bankPath = path.join(dictionaryPath, bankFile);
     let rawText: string;
     try {
-      rawText = fs.readFileSync(bankPath, 'utf-8');
+      rawText = await fs.readFile(bankPath, 'utf-8');
     } catch {
       log(`Failed to read frequency dictionary file ${bankPath}`);
       continue;
@@ -151,6 +168,7 @@ function collectDictionaryFromPath(
 
     let rawEntries: unknown;
     try {
+      await yieldToEventLoop();
       rawEntries = JSON.parse(rawText) as unknown;
     } catch {
       log(`Failed to parse frequency dictionary file as JSON: ${bankPath}`);
@@ -158,7 +176,7 @@ function collectDictionaryFromPath(
     }
 
     const beforeSize = terms.size;
-    const { duplicateCount } = addEntriesToMap(rawEntries, terms);
+    const { duplicateCount } = await addEntriesToMap(rawEntries, terms);
     if (duplicateCount > 0) {
       log(
         `Frequency dictionary ignored ${duplicateCount} duplicate term entr${
@@ -185,11 +203,11 @@ export async function createFrequencyDictionaryLookup(
     let isDirectory = false;
 
     try {
-      if (!fs.existsSync(dictionaryPath)) {
+      isDirectory = (await fs.stat(dictionaryPath)).isDirectory();
+    } catch (error) {
+      if (isErrorCode(error, 'ENOENT')) {
         continue;
       }
-      isDirectory = fs.statSync(dictionaryPath).isDirectory();
-    } catch (error) {
       options.log(
         `Failed to inspect frequency dictionary path ${dictionaryPath}: ${String(error)}`,
       );
@@ -201,7 +219,7 @@ export async function createFrequencyDictionaryLookup(
     }
 
     foundDictionaryPathCount += 1;
-    const terms = collectDictionaryFromPath(dictionaryPath, options.log);
+    const terms = await collectDictionaryFromPath(dictionaryPath, options.log);
     if (terms.size > 0) {
       options.log(`Frequency dictionary loaded from ${dictionaryPath} (${terms.size} entries)`);
       return (term: string): number | null => {

src/core/services/jlpt-vocab.test.ts

@@ -0,0 +1,72 @@
+import assert from 'node:assert/strict';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+
+import { createJlptVocabularyLookup } from './jlpt-vocab';
+
+test('createJlptVocabularyLookup loads JLPT bank entries and resolves known levels', async () => {
+  const logs: string[] = [];
+  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-jlpt-dict-'));
+  fs.writeFileSync(
+    path.join(tempDir, 'term_meta_bank_5.json'),
+    JSON.stringify([
+      ['猫', 1, { frequency: { displayValue: 1 } }],
+      ['犬', 2, { frequency: { displayValue: 2 } }],
+    ]),
+  );
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_1.json'), JSON.stringify([]));
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_2.json'), JSON.stringify([]));
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_3.json'), JSON.stringify([]));
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_4.json'), JSON.stringify([]));
+
+  const lookup = await createJlptVocabularyLookup({
+    searchPaths: [tempDir],
+    log: (message) => {
+      logs.push(message);
+    },
+  });
+
+  assert.equal(lookup('猫'), 'N5');
+  assert.equal(lookup('犬'), 'N5');
+  assert.equal(lookup('鳥'), null);
+  assert.equal(logs.some((entry) => entry.includes('JLPT dictionary loaded from')), true);
+});
+
+test('createJlptVocabularyLookup does not require synchronous fs APIs', async () => {
+  const tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-jlpt-dict-'));
+  fs.writeFileSync(
+    path.join(tempDir, 'term_meta_bank_4.json'),
+    JSON.stringify([['見る', 1, { frequency: { displayValue: 3 } }]]),
+  );
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_1.json'), JSON.stringify([]));
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_2.json'), JSON.stringify([]));
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_3.json'), JSON.stringify([]));
+  fs.writeFileSync(path.join(tempDir, 'term_meta_bank_5.json'), JSON.stringify([]));
+
+  const readFileSync = fs.readFileSync;
+  const statSync = fs.statSync;
+  const existsSync = fs.existsSync;
+  (fs as unknown as Record<string, unknown>).readFileSync = () => {
+    throw new Error('sync read disabled');
+  };
+  (fs as unknown as Record<string, unknown>).statSync = () => {
+    throw new Error('sync stat disabled');
+  };
+  (fs as unknown as Record<string, unknown>).existsSync = () => {
+    throw new Error('sync exists disabled');
+  };
+
+  try {
+    const lookup = await createJlptVocabularyLookup({
+      searchPaths: [tempDir],
+      log: () => undefined,
+    });
+    assert.equal(lookup('見る'), 'N4');
+  } finally {
+    (fs as unknown as Record<string, unknown>).readFileSync = readFileSync;
+    (fs as unknown as Record<string, unknown>).statSync = statSync;
+    (fs as unknown as Record<string, unknown>).existsSync = existsSync;
+  }
+});

src/core/services/jlpt-vocab.ts

@@ -1,4 +1,4 @@
-import * as fs from 'fs';
+import * as fs from 'node:fs/promises';
 import * as path from 'path';
 
 import type { JlptLevel } from '../../types';
@@ -24,6 +24,17 @@ const JLPT_LEVEL_PRECEDENCE: Record<JlptLevel, number> = {
 };
 
 const NOOP_LOOKUP = (): null => null;
+const ENTRY_YIELD_INTERVAL = 5000;
+
+function isErrorCode(error: unknown, code: string): boolean {
+  return Boolean(error && typeof error === 'object' && (error as { code?: unknown }).code === code);
+}
+
+async function yieldToEventLoop(): Promise<void> {
+  await new Promise<void>((resolve) => {
+    setImmediate(resolve);
+  });
+}
 
 function normalizeJlptTerm(value: string): string {
   return value.trim();
@@ -36,12 +47,12 @@ function hasFrequencyDisplayValue(meta: unknown): boolean {
   return Object.prototype.hasOwnProperty.call(frequency as Record<string, unknown>, 'displayValue');
 }
 
-function addEntriesToMap(
+async function addEntriesToMap(
   rawEntries: unknown,
   level: JlptLevel,
   terms: Map<string, JlptLevel>,
   log: (message: string) => void,
-): void {
+): Promise<void> {
   const shouldUpdateLevel = (
     existingLevel: JlptLevel | undefined,
     incomingLevel: JlptLevel,
@@ -53,7 +64,13 @@ function addEntriesToMap(
     return;
   }
 
+  let processedCount = 0;
   for (const rawEntry of rawEntries) {
+    processedCount += 1;
+    if (processedCount % ENTRY_YIELD_INTERVAL === 0) {
+      await yieldToEventLoop();
+    }
+
     if (!Array.isArray(rawEntry)) {
       continue;
     }
@@ -84,22 +101,31 @@ function addEntriesToMap(
   }
 }
 
-function collectDictionaryFromPath(
+async function collectDictionaryFromPath(
   dictionaryPath: string,
   log: (message: string) => void,
-): Map<string, JlptLevel> {
+): Promise<Map<string, JlptLevel>> {
   const terms = new Map<string, JlptLevel>();
 
   for (const bank of JLPT_BANK_FILES) {
     const bankPath = path.join(dictionaryPath, bank.filename);
-    if (!fs.existsSync(bankPath)) {
-      log(`JLPT bank file missing for ${bank.level}: ${bankPath}`);
+    try {
+      if (!(await fs.stat(bankPath)).isFile()) {
+        log(`JLPT bank file missing for ${bank.level}: ${bankPath}`);
+        continue;
+      }
+    } catch (error) {
+      if (isErrorCode(error, 'ENOENT')) {
+        log(`JLPT bank file missing for ${bank.level}: ${bankPath}`);
+        continue;
+      }
+      log(`Failed to inspect JLPT bank file ${bankPath}: ${String(error)}`);
       continue;
     }
 
     let rawText: string;
     try {
-      rawText = fs.readFileSync(bankPath, 'utf-8');
+      rawText = await fs.readFile(bankPath, 'utf-8');
     } catch {
       log(`Failed to read JLPT bank file ${bankPath}`);
       continue;
@@ -107,6 +133,7 @@ function collectDictionaryFromPath(
 
     let rawEntries: unknown;
     try {
+      await yieldToEventLoop();
       rawEntries = JSON.parse(rawText) as unknown;
     } catch {
       log(`Failed to parse JLPT bank file as JSON: ${bankPath}`);
@@ -119,7 +146,7 @@ function collectDictionaryFromPath(
     }
 
     const beforeSize = terms.size;
-    addEntriesToMap(rawEntries, bank.level, terms, log);
+    await addEntriesToMap(rawEntries, bank.level, terms, log);
     if (terms.size === beforeSize) {
       log(`JLPT bank file contained no extractable entries: ${bankPath}`);
     }
@@ -137,17 +164,21 @@ export async function createJlptVocabularyLookup(
   const resolvedBanks: string[] = [];
   for (const dictionaryPath of options.searchPaths) {
     attemptedPaths.push(dictionaryPath);
-    if (!fs.existsSync(dictionaryPath)) {
-      continue;
-    }
-
-    if (!fs.statSync(dictionaryPath).isDirectory()) {
+    let isDirectory = false;
+    try {
+      isDirectory = (await fs.stat(dictionaryPath)).isDirectory();
+    } catch (error) {
+      if (isErrorCode(error, 'ENOENT')) {
+        continue;
+      }
+      options.log(`Failed to inspect JLPT dictionary path ${dictionaryPath}: ${String(error)}`);
       continue;
     }
+    if (!isDirectory) continue;
 
     foundDictionaryPathCount += 1;
 
-    const terms = collectDictionaryFromPath(dictionaryPath, options.log);
+    const terms = await collectDictionaryFromPath(dictionaryPath, options.log);
     if (terms.size > 0) {
       resolvedBanks.push(dictionaryPath);
       foundBankCount += 1;

src/main/runtime/composers/mpv-runtime-composer.test.ts

@@ -22,6 +22,14 @@ const BASE_METRICS: MpvSubtitleRenderMetrics = {
   osdDimensions: null,
 };
 
+function createDeferred(): { promise: Promise<void>; resolve: () => void } {
+  let resolve!: () => void;
+  const promise = new Promise<void>((nextResolve) => {
+    resolve = nextResolve;
+  });
+  return { promise, resolve };
+}
+
 test('composeMpvRuntimeHandlers returns callable handlers and forwards to injected deps', async () => {
   const calls: string[] = [];
   let started = false;
@@ -516,3 +524,137 @@ test('composeMpvRuntimeHandlers runs tokenization warmup once across sequential
   assert.equal(prewarmJlptCalls, 1);
   assert.equal(prewarmFrequencyCalls, 1);
 });
+
+test('composeMpvRuntimeHandlers does not block first tokenization on dictionary or MeCab warmup', async () => {
+  const jlptDeferred = createDeferred();
+  const frequencyDeferred = createDeferred();
+  const mecabDeferred = createDeferred();
+  let tokenizeResolved = false;
+
+  const composed = composeMpvRuntimeHandlers<
+    { connect: () => void; on: () => void },
+    { isKnownWord: () => boolean },
+    { text: string }
+  >({
+    bindMpvMainEventHandlersMainDeps: {
+      appState: {
+        initialArgs: null,
+        overlayRuntimeInitialized: true,
+        mpvClient: null,
+        immersionTracker: null,
+        subtitleTimingTracker: null,
+        currentSubText: '',
+        currentSubAssText: '',
+        playbackPaused: null,
+        previousSecondarySubVisibility: null,
+      },
+      getQuitOnDisconnectArmed: () => false,
+      scheduleQuitCheck: () => {},
+      quitApp: () => {},
+      reportJellyfinRemoteStopped: () => {},
+      syncOverlayMpvSubtitleSuppression: () => {},
+      maybeRunAnilistPostWatchUpdate: async () => {},
+      logSubtitleTimingError: () => {},
+      broadcastToOverlayWindows: () => {},
+      onSubtitleChange: () => {},
+      refreshDiscordPresence: () => {},
+      ensureImmersionTrackerInitialized: () => {},
+      updateCurrentMediaPath: () => {},
+      restoreMpvSubVisibility: () => {},
+      getCurrentAnilistMediaKey: () => null,
+      resetAnilistMediaTracking: () => {},
+      maybeProbeAnilistDuration: () => {},
+      ensureAnilistMediaGuess: () => {},
+      syncImmersionMediaState: () => {},
+      updateCurrentMediaTitle: () => {},
+      resetAnilistMediaGuessState: () => {},
+      reportJellyfinRemoteProgress: () => {},
+      updateSubtitleRenderMetrics: () => {},
+    },
+    mpvClientRuntimeServiceFactoryMainDeps: {
+      createClient: class {
+        connect(): void {}
+        on(): void {}
+      },
+      getSocketPath: () => '/tmp/mpv.sock',
+      getResolvedConfig: () => ({ auto_start_overlay: false }),
+      isAutoStartOverlayEnabled: () => false,
+      setOverlayVisible: () => {},
+      isVisibleOverlayVisible: () => false,
+      getReconnectTimer: () => null,
+      setReconnectTimer: () => {},
+    },
+    updateMpvSubtitleRenderMetricsMainDeps: {
+      getCurrentMetrics: () => BASE_METRICS,
+      setCurrentMetrics: () => {},
+      applyPatch: (current, patch) => ({ next: { ...current, ...patch }, changed: true }),
+      broadcastMetrics: () => {},
+    },
+    tokenizer: {
+      buildTokenizerDepsMainDeps: {
+        getYomitanExt: () => null,
+        getYomitanParserWindow: () => null,
+        setYomitanParserWindow: () => {},
+        getYomitanParserReadyPromise: () => null,
+        setYomitanParserReadyPromise: () => {},
+        getYomitanParserInitPromise: () => null,
+        setYomitanParserInitPromise: () => {},
+        isKnownWord: () => false,
+        recordLookup: () => {},
+        getKnownWordMatchMode: () => 'headword',
+        getNPlusOneEnabled: () => true,
+        getMinSentenceWordsForNPlusOne: () => 3,
+        getJlptLevel: () => null,
+        getJlptEnabled: () => true,
+        getFrequencyDictionaryEnabled: () => true,
+        getFrequencyDictionaryMatchMode: () => 'headword',
+        getFrequencyRank: () => null,
+        getYomitanGroupDebugEnabled: () => false,
+        getMecabTokenizer: () => null,
+      },
+      createTokenizerRuntimeDeps: () => ({ isKnownWord: () => false }),
+      tokenizeSubtitle: async (text) => ({ text }),
+      createMecabTokenizerAndCheckMainDeps: {
+        getMecabTokenizer: () => null,
+        setMecabTokenizer: () => {},
+        createMecabTokenizer: () => ({ id: 'mecab' }),
+        checkAvailability: async () => mecabDeferred.promise,
+      },
+      prewarmSubtitleDictionariesMainDeps: {
+        ensureJlptDictionaryLookup: async () => jlptDeferred.promise,
+        ensureFrequencyDictionaryLookup: async () => frequencyDeferred.promise,
+      },
+    },
+    warmups: {
+      launchBackgroundWarmupTaskMainDeps: {
+        now: () => 0,
+        logDebug: () => {},
+        logWarn: () => {},
+      },
+      startBackgroundWarmupsMainDeps: {
+        getStarted: () => false,
+        setStarted: () => {},
+        isTexthookerOnlyMode: () => false,
+        ensureYomitanExtensionLoaded: async () => undefined,
+        shouldWarmupMecab: () => false,
+        shouldWarmupYomitanExtension: () => false,
+        shouldWarmupSubtitleDictionaries: () => false,
+        shouldWarmupJellyfinRemoteSession: () => false,
+        shouldAutoConnectJellyfinRemote: () => false,
+        startJellyfinRemoteSession: async () => {},
+      },
+    },
+  });
+
+  const tokenizePromise = composed.tokenizeSubtitle('first line').then(() => {
+    tokenizeResolved = true;
+  });
+  await new Promise<void>((resolve) => setImmediate(resolve));
+  assert.equal(tokenizeResolved, true);
+
+  jlptDeferred.resolve();
+  frequencyDeferred.resolve();
+  mecabDeferred.resolve();
+  await tokenizePromise;
+  await composed.startTokenizationWarmups();
+});

src/main/runtime/composers/mpv-runtime-composer.ts

@@ -142,21 +142,40 @@ export function composeMpvRuntimeHandlers<
     return nPlusOneEnabled || jlptEnabled || frequencyEnabled;
   };
   let tokenizationWarmupInFlight: Promise<void> | null = null;
+  let tokenizationPrerequisiteWarmupInFlight: Promise<void> | null = null;
+  let tokenizationPrerequisiteWarmupCompleted = false;
   let tokenizationWarmupCompleted = false;
+  const ensureTokenizationPrerequisites = (): Promise<void> => {
+    if (tokenizationPrerequisiteWarmupCompleted) {
+      return Promise.resolve();
+    }
+    if (!tokenizationPrerequisiteWarmupInFlight) {
+      tokenizationPrerequisiteWarmupInFlight = options.warmups.startBackgroundWarmupsMainDeps
+        .ensureYomitanExtensionLoaded()
+        .then(() => {
+          tokenizationPrerequisiteWarmupCompleted = true;
+        })
+        .finally(() => {
+          tokenizationPrerequisiteWarmupInFlight = null;
+        });
+    }
+    return tokenizationPrerequisiteWarmupInFlight;
+  };
   const startTokenizationWarmups = (): Promise<void> => {
     if (tokenizationWarmupCompleted) {
       return Promise.resolve();
     }
     if (!tokenizationWarmupInFlight) {
       tokenizationWarmupInFlight = (async () => {
-        await options.warmups.startBackgroundWarmupsMainDeps.ensureYomitanExtensionLoaded();
+        const warmupTasks: Promise<unknown>[] = [ensureTokenizationPrerequisites()];
         if (
           shouldInitializeMecabForAnnotations() &&
           !options.tokenizer.createMecabTokenizerAndCheckMainDeps.getMecabTokenizer()
         ) {
-          await createMecabTokenizerAndCheck().catch(() => {});
+          warmupTasks.push(createMecabTokenizerAndCheck().catch(() => {}));
         }
-        await prewarmSubtitleDictionaries({ showLoadingOsd: true });
+        warmupTasks.push(prewarmSubtitleDictionaries({ showLoadingOsd: true }).catch(() => {}));
+        await Promise.all(warmupTasks);
         tokenizationWarmupCompleted = true;
       })().finally(() => {
         tokenizationWarmupInFlight = null;
@@ -165,9 +184,8 @@ export function composeMpvRuntimeHandlers<
     return tokenizationWarmupInFlight;
   };
   const tokenizeSubtitle = async (text: string): Promise<TTokenizedSubtitle> => {
-    if (!tokenizationWarmupCompleted) {
-      await startTokenizationWarmups();
-    }
+    if (!tokenizationWarmupCompleted) void startTokenizationWarmups();
+    await ensureTokenizationPrerequisites();
     return options.tokenizer.tokenizeSubtitle(
       text,
       options.tokenizer.createTokenizerRuntimeDeps(buildTokenizerDepsHandler()),