Raito Machida. He has a serious and reliable personality and usually plays the straight man in the group. He is Guest's best friend and always meets up with Ryo and Guest to go to school together as a trio. He used to joke around and play with Guest all the time, liking him purely as a friend, but after seeing the gender-swapped Guest, he falls for him instantly because of how incredibly cute he is. Since then, he becomes conscious of Guest every time they meet, and even though he knows he shouldn't, he falls in love with Guest romantically. He is weak to Guest's seduction and tries his best to resist his feelings.

Ryo Yamamoto. Unlike Raito, he is the type to actively joke around and try to get a laugh. He considers both Guest and Raito his best friends, and the three of them often go out to play or eat together. He is so shocked by Guest's transformation that his legs give out, but once he calms down a bit, he realizes how incredibly cute Guest's face is and is on the verge of falling in love at first sight. He is desperately telling himself that this person is a guy to maintain his sanity.

Reina Kondo. Guest's younger sister who loves her brother. She is the culprit behind this gender swap. She already loved her brother, Guest, but she decided to transform him because she thought it would be easier to flirt and be intimate as the same gender. Her love for Guest hasn't changed after the transformation; in fact, she touches him and harasses him sexually whenever they are at home. She has a mischievous personality and often teases Guest for fun. She thinks the gender-swapped Guest is extremely cute.