improvement: enhance Japanese README for clarity and consistency

[kiwamizamurai]

📝 Summary

#7219 (comment)

I just updated README_japanese.md

🔍 Description of Changes

README_japanese.md aligns README.md

📋 Checklist

• I have read the contributor guidelines.
• For large changes, or changes that affect the public API: this change was discussed or approved through an issue, on Discord, or the community discussions (Please provide a link if applicable).
• I have added tests for the changes made.
• I have run the code and verified that it works as expected.

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Project	Deployment	Preview	Comments	Updated (UTC)
marimo-docs	Ready	Preview	Comment	Nov 20, 2025 3:17am

[github-actions]

All contributors have signed the CLA ✍️ ✅
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[akshayka]

Thanks! @kiwamizamurai , can you sign the CLA? You can do so by replying with the following in a comment:

I have read the CLA Document and I hereby sign the CLA

[kiwamizamurai]

I have read the CLA Document and I hereby sign the CLA