Crazy ask- trying to find a manga

This is probably a long shot, but I’m trying to find a BL manga from manga rock that I couldn’t finish. I don’t remember a lot, but this is some of the impressions I got:
1. Around mid to late 2010’s
2. Japanese manga; not Korean WEBTOON
3. Premise was bittersweet/a bit tragic. The couple loved each other but couldn’t be together? Maybe was unrequited?
4. Slowburn
5. The storyline goes through different seasons and different parts/generations of their lives
6. had a red thread/string of fate theme? Not 100% confident on this
7. Was a rlly good story lol. And I think was leading up to an eventual happy ending? I didn’t finish it tho hahah

Bless any angel who is able to help me find this manga.