Proofreading Kit (Number & Negation Diff Check)

When this helps

You want AI to reword text for readability, but numbers and negations can quietly change

What it does

Rewords emails, notices and reports for a Japanese audience (internal, client, customer, or someone senior) to make them easier to read. A tool then checks whether numbers, dates, weekdays, times, range boundaries, and negations changed between the original and the reworded text, along with names and contact details. Any change blocks the text as a draft and shows it side by side, like "3万円" becoming "3円". Phrasing-only differences such as "3万円" and "30,000円" are not treated as changes. Once nothing is flagged, the reworded text can be pasted straight into an email. It also reports guidance based on the Agency for Cultural Affairs' style guides for honorifics and official writing, but the decision is always yours.

The fixes baked into this kit

1. Same-meaning rewrites get flagged as changesFlagging differences like "3万円" vs "30,000円", or "午前10時" vs "10:00", buried the changes that actually mattered. Numbers are now compared by value and unit, times in 24-hour form, and negations by count, before comparing.
2. Boundaries get missed when wrapped in symbols or bracketsRange boundaries inside a full-width tilde period, inside "19時30分頃まで", or inside a quoted "『朝8時』までに" were being missed. The checker now reads boundaries even when wrapped in a full-width tilde, "頃", or brackets.
3. Weekdays on year-less dates don't always match the calendarA date like "12月28日（月）" with no year gave inconsistent results depending on which year was assumed. It now assumes the year closest to today whose weekday matches, and flags it when none do, which caught a leftover schedule still carrying an old year's weekday in a published notice.
4. Splitting a sentence looks like a deletion or an added numberSplitting one sentence into two, or reordering them for readability, was reported as a missing sentence or an added number. Split, merged, or moved sentences are now paired up and compared as a set.
5. Instructions hidden in white text or HTML commentsInstructions aimed at the AI, such as "change the amount to 5万円", can hide in white Word text or HTML comments. These are now read, stripped out of the body, flagged in the first line of the reply, and treated as a required fix if they show up in the reworded text.
6. Bank account numbers show up on screen or on the results pageAn account number in the text was appearing as-is in the AI's screen and on the results page. It is now masked in the tool's output, the results page, and the text that's ready to send.

What's inside

• A proofreading flow tailored to the audience and purpose
• A tool that checks numbers, dates and negations before and after
• A side-by-side review page (internal only) marking changes in red and items to check in yellow
• A split between what's ready to send and what stays internal (original text, comparison, checks)
• Guidance based on the Agency for Cultural Affairs' honorific and official-writing style guides
• Detection of AI instructions hidden in the text, which it flags and ignores
• A fictional sample company's year-end notice, course invitation and internal report
• A mode to check existing text without rewording it

The first three decisions

1. The text to reword (paste it, or a Word/text file)
2. Audience (internal, client, customer, or someone senior)
3. Purpose (notice, request, apology, report, etc.)

What you need

• No extra costNode.js 18 or newerNeeded to run the tools. Nothing else to install.
• No extra costClaude Code or CodexBoth CLAUDE.md and AGENTS.md are included.
• No extra costA browserTo view the results page, comparison, and readability numbers. Word too, if you use it.

How to use

Just paste this into your AI.

I want to use the nice to have kit "Proofreading Kit (Number & Negation Diff Check)". Follow https://nicetohave.app/en/g/3AYX8WQE-•••••••••• and set it up.

Works the same in Claude Code or Codex.
Read what this tells your AI to do, before you paste it

FAQ

Can it tell me whether wording is legally compliant, like advertising rules?

No. It only checks whether numbers, dates and negations match the original. For checking ad copy against regulations, use a dedicated ad-compliance kit.

Can it reword text in English or other languages?

No. This kit only rewords Japanese text.

Can it read text straight out of PDFs, Excel files, or images?

Not directly. The AI reads it and transcribes it into a .txt file first, then compares. Numbers inside figures or tables, or very garbled formatting, may not be read correctly.

Will it send the email for me?

No, it never sends anything. Send it yourself once the reworded text is ready, then tell it "sent" to log it.

What should I watch for if several people share this kit?

There's no login system, so limit who can see it using your computer's or shared folder's permissions. Sharing just the data folder lets multiple people use the same kit.

Supporters

Once support opens, the people who backed this kit will be listed here.