He was genuinely heartbroken when Hatako didn’t say he loved him back. And I literally cried while reading that scene. I’m not even upset he and Hatako didn’t end up together. I even think him choosing to get married made sense for him because of the cultural pressure he felt from his family, the fact Hatako was unable to return his earnest feelings, and the genuine respect he had for his marriage partner.
He was objectively wrong for Hatako because Hatako’s heart didn’t race when they were together, and Masato was objectively a better boyfriend than Chika (who was too pushy & broke up with him in front of all of their friends), but he truly loved Hatako and wanted to be with him. He apologized for the bondage incident and was actively trying to change his bad habits (e.g., smoking, not listening to him) to be a better boyfriend. He was never just playing around with Hatako. Chika made a lot of mistakes, but their sex was consensual (though the bondage incident was obviously questionable) and he was always honest about his intentions.
What makes me upset is Hatako interpreted that moment (asking him to say I love you) as Chika being selfish again when that was actually his least selfish act in the entire story. He knew Hatako would probably still keep passively going along with whatever he wanted, so he consciously chose to leave his apartment (instead of trying to have sex) and earnestly asked (not told) Hatako to say he loved him. He even broke up with him (when there was still a chance Hatako might eventually fall for him) and intentionally chose to be the bad guy because he didn’t want Hatako to get hurt later. I would honestly be satisfied if they could have just had a real, honest conversation about their feelings. Hatako could apologize for not loving him back, acknowledge he genuinely started to care about him when they were together, and thank him for indirectly helping him find true love with Masato.
I’m at least glad he wasn’t treated like a villain in the end, but I’m still sad he was relegated to a petty side character after we had seen so much emotional development from him in the first volume. Also, Masato is just a boring character to me because he had no flaws or personality other than immediately taking advantage of the break-up between his two close friends.