“What would you do if I told you your partner that day was 'me'?” Gen, a hairdresser, has long been in love with his older childhood friend, Koutarou, who likes his older brother, Kanade. One night, Gen spends the night at a hotel with a drunken Koutarou, bolstered by the thought that he might have a chance. However, Koutarou mistakenly thinks it was his older brother, Kanade, that he slept with. Gen's used to being mistaken as Kanade, but they felt each other's heat– to think he was mistaken as him even at night–. A devoted, younger, handsome hairdresser x a naturally airheaded, devilish, older, plain-faced boy's one-sided, childhood love!