Organizing LINE Chats When You Suspect an Affair, General Info and Limits
This article is general information about organizing chats you sent or received as a participant. It does not cover information obtained by looking into another person's device or account without permission. It also says nothing about whether an affair can be established or what compensation might be possible.
Not legal advice. This page is general information. Whether a court admits or relies on a chat is for the court; convokeep does not promise admission or any outcome. Ask a qualified lawyer about your case.
Which chats can I organize?
The history of chat rooms you take part in, on your own account. Do not collect information by looking at the other person's phone, guessing a password and logging in, or similar methods. Accessing someone else's account with their ID or password without permission may fall under Japan's Unauthorized Computer Access Prohibition Act and similar laws (we could not open the statute text in this check).
How do I organize them?
Send the chat history as text and keep it as the original, then choose a date range and make a PDF. For the steps, see How to send LINE chat history.
What about third parties' information?
If the chat includes information about unrelated people, such as names or face photos, check whether it needs to be covered before you submit or share it.
Will this be accepted?
Whether it is accepted, and how much weight it carries, is decided case by case by the court or similar body. This article does not promise any result.
Who should I ask?
Talk to a lawyer, or to the general guidance of Houterasu (Japan Legal Support Center).
What if I am struggling emotionally?
Do not carry it alone. Talk to someone you trust or to a professional support service.
Privacy
Reading the file, building the PDF and calculating hashes all happen in your browser. No chat or attachment is uploaded and there is no account. See the privacy policy and the disclaimer.
Related guides
- Keeping LINE chats as evidence
- Before giving LINE evidence to a lawyer
- What a hash value does and does not tell you
- Saving LINE chats on iPhone and Android
Sources (checked 2026-10-29)
- Houterasu (Japan Legal Support Center): https://www.houterasu.or.jp/ (opened and checked. Support Dial 0570-078374, weekdays 9:00-21:00, Saturdays 9:00-17:00)
- LINE Help, "Send chat history": https://help.line.me/ (contentId 20007388. Menu: Settings > Send chat history. Only the history currently shown is saved; the text format cannot be restored. Content opened and checked in T193 and T203-CL.)
Ready to try it?
Drop your exported .txt file on the convokeep app for a free preview. The first 3 pages are free (watermarked, no integrity page); saving the full PDF is a one-time paid feature. No chat or attachment is uploaded: the file is read in your browser. To check later that a file is unchanged, use the hash checker.
This document was generated locally in the user's browser; no content was uploaded.