Boy A (Yu-won) : gay, poor, no.1 student, re-test taker, pro manipulator, sick mom, childhood trauma, didn't say but actually really loves Boy B,
Boy B (Hee-bum) : straight, but loves Boy A, illegitimate son of Plotinian, lonely, straightforward, bold, slowly realized feeling for Girl, actually cute one, sticker as a hobby.
Girl (Jumi) : ordinary highschool graduate, kind, secret keeper, loves boy B but support their relationship,
That Summer (kim Hyun)