I'm a sucker for female/male duets, and the video is lovely.

And right at the end, there's a line that goes
離れてからどうしている？
左薬指は開いたまま
(How have you been since we broke up? My/your left ring finger is still empty)
... and because Japanese leaves so much to context, it's impossible to know if it's "my" or "your". But given the next line is でも僕よりもっといい人に出会ってね (but I hope you'll find someone better than me) I'd pick "your".

UNFAIR RULE「思い出になってよ (feat. 橘高 連太郎)」
https://youtube.com/watch?v=GrCOJyugK_s&si=pE8hUtzj9xgfi_I2