Haru-chan is introduced as bisexual. Bisexuality issues, especially from multiple women's point-of-view, are represented.
LGBT representation! With a couple that has a butch bisexual and femme lesbian.
Camilo states he's bisexual. There's more discussion on attraction from a bisexual's point-of-view.
Kazushi states he's bi. More than that, there's actual bisexuality issues (in a BL no less!) represented in the story.
A major side character states he's bi. He has, for a time, also referred to himself as female and has taken to calling older women as "unnie" (if you're male, you'd call them as "noona").
Content Warning: contains graphic depictions of rape.
Sangho states he's bisexual. Also shows ex-girlfriends. The comics delve a bit into bisexuality and has some subtle depiction of bi erasure.
Kengo states he's bisexual.
Ozaki is bisexual. Insists on it, matter of fact.
Sensei says he doesn't care about gender. Shin states sensei is bi.
Okachimachi states he doesn't care about gender.
Happy Picture Diary