You can "announce" things like messages you've sent and received, polls you created, and events so they permanently appear at the top of a chat.
Note: From LINE version 12.19.0, system messages will appear in chats after making announcements.
To announce messages:
1. Tap and hold the message you want to announce.
2. Tap Announce.
To announce polls:
1. Tap "+" at the bottom of the chat screen.
2. Tap Poll and then the poll you want to announce.
3. Tap Announce > OK.
To announce events:
1. Tap the menu icon at the top of the chat screen.
2. Tap Events and then the event you want to announce.
3. Tap Set as announcement > OK.
Let us know if we can make it better.