Exactly. Mafuyu and Ue will just have to deal with the fact that Mafu will never ever get over Yuki 100% and that's alright. It doesn't make Mafu selfish or unfair towards Ue, it's a death of a lover through suicide. He will carry that his whole life because Mafuyu and Yuki truly belonged to each other and the amount of their history and love even makes that gaping hole in Mafuyu's heart more persistent. There will never ever be a closure. Sadly.
Yuki wasn't just Mafuyu's lover or boyfriend, they were best friends since childhood too. You can't leave that fact out or forget it, it's incredibly important.
Hence, me talking about their history together. Them being best friends is part of said history, is it not? Therefore, I didn't forget about it.
Don't expect romance in Given like any stereotypical bl plot. This is much more than just romance, its a broken story about grieve and trauma. It's going to be heavy cause the weight that Mafu carries will not vanish easily. Yuki is not a part of Mafu's past, YUKI IS HIS PAST. It might be frustrating but pls, understand that Yuki and Mafu were legit soul mates. And even thou, Mafu likes Ue rn, it's going to take him long and long to forget Yuki. This is not a perfect romance story, it never will be. Accept them to be broken characters