This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Future Lovers
Kento has had to deal with the death of his parents, being raised by his grandparents. He tries to propose marriage (Or, at least, registry adoption) to his boyfriend Akira, but Akira turns him down, because of Kento's grandparents' opposition to their relationship, among other things, and says that he'll only go along with the adoption when Kento's grandfather (Their biggest opponent) dies, as a bad joke. Kento's ex-girlfriend announces that she's going to be married, and moving far away with her new husband, and then his grandfather slips and falls, injuring himself enough to have to go to the hospital and scaring just about everyone in their family, including Akira. In a drunken mess, Kento tearfully confesses to Akira that he fears everyone abandoning him someday, and he's terrified of Akira going away, too. The wayAkira's feelings about the situation are presented.
The saddest part for this troper was realizing how much he cared for Yukie. It always seemed like he was mostly interested in her because she fit his housewife ideal, but this moment really makes it clear she's his friend and he's seriously going to miss her.
You forgot the next twopages, which really hammer the emotional impact home. Especially when you consider how Akira's reaction upon waking up is most likely a Call Back to Kento's reaction to a dream of him and Akira growing old together in the previous volume.