Kanga na Spoon
Chapters 1-5 are a great love story between longtime friends. Chapter six veers into abusive noncon territory but features an on-page wedding, only the second I can remember seeing (the other in Haru wo Diete Ita). The final chapter is two high school students with mutual crushes.
Natsukage Ni, Sayonara
Two boys who meet through a part-time summer job fall into an innocent first love. (First few & final chapter) Childhood friends who discovered intimacy with each other haven't spoken for five years after they were caught & are reunited.
blanc
As their relationship continues to mature, Sajou realizes he can no longer envision his future and asks for some time apart from Kusakabe, who then revokes the privilege of calling him by his first name. If you love these two, you might want to wait for this to be completed or at least get a few more chapters in, because I feel like I've been betrayed. ETA:
Please Greet the New Bride