I built an app called YomiPlay — it turns Japanese audio and video into watchable, shadowable, editable, shareable learning material

YomiPlay started from a very engineer-brained thought.

Working at a Japanese company, we record the screen during code review meetings so we can replay them later and double-check requirements and edge cases.

The reality, though: replaying audio and video alone is awkward, and the cognitive cost is high. Japanese meetings are especially hard — fast speech, dense terminology, layered context. Even after several passes, things still slip through.

So I started asking:

Could I turn meeting recordings, podcasts, and YouTube videos directly into material I can listen to, see, edit, and review later?

That's where YomiPlay began.

Core idea: turn audio/video into an actionable subtitle workflow

YomiPlay isn't a single-purpose tool — it's a full pipeline:

Import audio/video → auto-transcribe subtitles → translate + add readings → polish the subtitles → click-to-play any sentence → save locally and export to share

Let me walk through what it can actually do, in the order you'd use it.

1. Multi-source import: bring in material however you want

You can grab study material in several ways:

• Upload local audio or video files
• Pull from a massive library of podcasts
• Download audio/video from YouTube and similar platforms

That means you don't have to change your content habits. Whether it's a work meeting recording, a tech interview, a Japanese podcast, or a Japanese YouTube channel — they all flow into the same learning pipeline.

Import sources	Podcast browser

2. Auto-transcribe: turn "I can't quite catch it" into "I can see it"

Once imported, YomiPlay uses an AI model to transcribe the audio/video into subtitle text.

This step solves the most fundamental — and most important — problem: structuring speech as text. Once speech becomes subtitles, comprehension jumps:

• No more blind listening
• Every point is rewindable and seekable
• Even long-form audio reveals its key sections quickly

3. Subtitles linked to playback: click a line, jump to that moment

YomiPlay lets subtitles drive playback in reverse:

• Click any subtitle to jump straight to that moment in the audio/video
• Loop a single sentence for intensive listening practice
• Re-find the exact discussion point during a meeting review

This is far more precise than dragging the progress bar, and ideal when you only want to review one specific line or paragraph.

4. Subtitle translation: switch to your native language to grasp the content

For Japanese learning or cross-language understanding, YomiPlay supports subtitle translation. You can render subtitles in a language you're more comfortable with for parallel reading.

The point isn't to replace the original — it's to:

• Lower the bar for first-pass comprehension
• Help you sanity-check meaning
• Free your attention for the truly tricky parts

5. Reading annotations: building on YomiMark's experience for Japanese readability

This is one of YomiPlay's distinctive capabilities. Drawing on what I learned building YomiMark, YomiPlay adds Japanese-specific learning aids:

• Japanese readings (furigana) — so you can lock in pronunciation quickly
• Loanword (katakana) readability support — surfacing the English original or its translation

For learners stuck in the "I sort of understand but can't read smoothly and can't catch it by ear" zone, this step is a big help.

6. Polish subtitles while listening: study material isn't "done" when it's generated

YomiPlay doesn't just auto-generate — it also lets you polish subtitles while you play:

• Listen and correct text as you go
• Turn machine output into something accurate and tuned for your own review
• Convert one-off content into long-term reference material

This is particularly useful for meeting reviews — you can lock in the exact meaning of key terms and requirements, and the act of polishing subtitles is itself a great learning loop.

Edit timeline	Reading editing

7. Local storage: building your private learning corpus

The final subtitle files are stored locally on your device — no network required while studying.

This means you can steadily accumulate your own Japanese corpus, used for:

• Shadowing practice
• Intensive-listening review
• Terminology recall
• Spoken-expression imitation

Beyond convenience, the real win is this: the more you consume, the more reusable material you've built up.

8. Export and share: from solo learning to co-learning

If you want, you can export the curated material and share it with friends or coworkers.

Going from solo study to co-learning multiplies the value of the same quality content.

Who is YomiPlay for?

• Engineers and professionals who need to review Japanese meeting recordings
• Japanese learners who want podcasts and YouTube as real-world source material
• Long-term learners who want to turn "I listened to it once" into "I have something to review"
• Content users who need subtitles that are editable, seekable, and exportable

Closing: I didn't build a "player" — I built a reusable learning loop

YomiPlay's goal is straightforward:

Turn audio/video from one-time consumption into trainable, reusable, shareable learning assets.

If you also struggle with "I can't catch it / I listen a lot but nothing sticks / reviewing is hard," YomiPlay was made for you. I hope it helps you convert every input into visible growth.

Developed with care by Toshiki.Tech