Yes, you can add furigana to a scanned Japanese PDF without retyping the page. Upload the PDF to Mooon, and it reads the Japanese directly from the page, rebuilds the content in natural reading order, and opens it as an editable Mooon Doc. Click Add Furigana, and readings are added above the corresponding words throughout the document.

Why most PDF furigana tools fail on scans

Most furigana generators expect you to paste in Japanese text. Tools that claim to support PDFs often depend on the text layer already embedded in the file. That approach only has a chance when the PDF is unusually clean and standard. Files like that are rare; even then, the order stored in the text layer does not guarantee that an extractor will follow the order a person reads the page.

Scanned PDFs have no text layer. Even non-scanned Japanese PDFs frequently contain vertical columns, unusual encodings, mixed images and text, or irregular layouts that make ordinary extraction incomplete or scrambled.

Mooon does not depend on that hidden layer. It reads what is visibly printed on the page—the characters, columns and layout—then reconstructs the content in the order a person would naturally read it. This kind of visual recognition is often called OCR, but you do not need to run a separate OCR tool or handle its raw output.

From scan to editable furigana

1. Upload the scanned PDF. There is no need to extract or retype the text first.
2. Mooon reads and rebuilds the page automatically. Vertical, multi-column, handwritten and other complex layouts become a continuous document in natural reading order.
3. The result opens as a Mooon Doc. The recognized body text is editable, so a misread character can be corrected in context.
4. Click Add Furigana. Mooon adds readings throughout the reconstructed document.
5. Review the difficult readings. Change the furigana for a name or word directly where it appears.

The entire process stays around one document. You do not have to move raw text from an OCR tool to a furigana generator and then into an editor while its structure and corrections fall apart.

Recognition is the foundation; furigana is the result

Once the scanned page has become reliable text in a Mooon Doc, Mooon can annotate the entire document. Its custom Japanese dictionary strengthens difficult readings around names, places, counters and specialized words. If the source character is wrong, edit the body text; if the pronunciation is wrong, edit the furigana. Neither correction requires you to regenerate the whole page.

The same PDF can also carry paragraph-by-paragraph translation and audio beside the source. Those capabilities remain part of the document, but the central result here is simple: a scan that no ordinary furigana generator could read becomes an editable document with full-text furigana.

FAQ

Can I add furigana if the PDF has no selectable text? Yes. Mooon reads the visible Japanese on the page, turns it into editable text, and then lets you add full-text furigana.

Does it work on vertical scanned pages? Yes. Mooon recognizes the columns and their reading order before rebuilding the content as a natural horizontal text flow.

Can I correct a character that was recognized incorrectly? Yes. The body text in the Mooon Doc is editable.

Can I correct a wrong name reading? Yes. Furigana can be edited for a word or name without regenerating the whole document.

Does my original scan get changed? No. Mooon creates a separate Mooon Doc and leaves the original PDF unchanged.

Add furigana to a scan other tools cannot read

Upload the scan, let Mooon reconstruct the page, then add full-text furigana in one click.