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The home page has two areas to help you get started quickly: Sentence of the day and Recent. Click any item in either area, and the app fills in the text and starts the analysis right away.

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Sentence of the day

The sentence of the day is a short Japanese sentence recommended each day. It comes with furigana and a translation in your current interface language. Click it to analyze the sentence.

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How sentences are generated

  • The sentence updates at midnight Japan time. Every visitor sees the same sentence all day.
  • The server generates it with AI once a day and caches the result. Later requests on the same day don’t call the model again.
  • Topics and grammar points rotate by date. With 19 topics and 17 grammar points, it takes 323 days before a combination repeats.
  • The difficulty is JLPT N5–N3, and the length is 10–28 characters. The content avoids topics such as personal names, brands, politics, religion, and disasters.
  • Translations are generated in four languages at once: 简体中文, 繁體中文, English, and 한국어.
  • After generation, the server validates the format and confirms that the tokens join back into the original sentence. If the sentence fails, it retries with a different one.

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Backup sentences

In the following cases, the home page shows a built-in backup sentence instead:
  • The server has no DEEPSEEK_API_KEY or GEMINI_API_KEY configured.
  • Generation fails, or the server can’t reach the model provider.
  • The request times out.
There are 7 backup sentences. They come pre-segmented with readings, rotate by date, and don’t call the AI.
The sentence of the day is generated only with the key configured on the server. It never uses keys that visitors enter in Settings. The server uses DeepSeek first and falls back to Gemini when there is no DeepSeek key.
If the home page keeps rotating among a few fixed sentences, the server has no usable key, or its outbound network can’t reach the model provider. For details, see Troubleshooting.

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Recent

After each successful analysis, the app saves the text to the Recent list.
  • Records are stored only in the current browser’s local storage and are never uploaded to the server.
  • Up to 50 records are kept. For identical texts, only the latest one is kept.
  • The home page shows the 3 most recent records by default. Click Show all N to see every record.
  • Click Clear history to delete all records.
In private browsing mode or in a browser with local storage disabled, the page shows “History cannot be saved to this browser right now and may be lost on refresh.”