Well it’s not a lie that in Japan in order to have a successful life as a human you must marry and have a family. I lived there that is indeed a big issue. It’s only logical that in a homosexual relationship in a country so close minded and where the pressure is so big that you wouldn’t take the risk to have your boyfriend being able to sleep with a girl. It’s not a phobia, I can understand the feeling to protect oneself from being hurt, the daily life is already hard as it is.
i'm not talking about the mc (he obviously had comphet) but his bf. idk as a bi person it always felt icky to me when gay men/lesbians only go for people who never slept with the oposite gender. i can get their logic, but it feels very invalidating if a bi person really loves you. i get that that wasn't the case in this story (ex bf was an asshole) but i'm talking about it more as a broad concept that i've noticed in many other works.
what's up with biphobia in a lot of mangas that try to deal with lgbt issues