I think it's in a different manga.
I forgot since I have to find all the series so I can't remember which manga is it.
They actually do give the rings. It was cute asf.
Try finding the other series, I think it was an extra chapter or something
from what i remember, they gave rings to each other when rihito is already in college (??) theres a short part showing rihito turned 20 and they both exchanged rings they bought
Oh it's here in graduation certificate artbook (●'◡'●)ﾉ
http://www.mangago.zone/read-manga/graduation_certificate_artbook/mh/c001/46/
ooooh!! thank you guys!!!!
hang on i’m so confused, I reread everything before blanc and I saw the chapter where they buy the rings but.... at what point do they actually give each other the rings??