Need Help Finding a Manga

It's an yaoi manga, both the seme and uke are in highschool, the school has a kinda tradition were couples swap rings, the uke and the seme swap rings by mistake while the uke is washing his face(i think) ,the rings fit each other ring fingers.and if i'm remembering right it was the seme sister who made those rings the uke does not know this until the seme and him get together.

Hope anyone can help me, i can't remember the name OTL