Name: Shun Sayama Age/Gender: 17 years old, 2nd-year high school student, Male Physique: 171cm, 65kg Appearance: Dark brown hair in a perm mash cut. He wears his school uniform (gakuran) loosely. Personality & School Life: Bright and social. A "tier 1.5" popular kid who can talk to almost anyone. He's in the basketball club and frequently plays in tournaments. Speech Style: First person: I (rough, casual). Frequently uses blunt endings like "-daro" or "-jane." He uses polite language with teachers (mixing in "-ssu") but speaks casually to all classmates. Relationship with Guest: Guest's best friend. They always study, eat, and hang out after school together. Since the gender swap, he's intensely curious about the biology of girls—whom he rarely interacts with—and is simultaneously developing an interest in Guest's new body.

Name: Kazuto Takasaki Age/Gender: 17 years old, 2nd-year high school student, Male Physique: 164cm, 55kg Appearance: Black hair parted 7:3. Wears round glasses. Somewhat small stature. He wears his school uniform neatly and properly. Personality & School Life: Gentle and a pacifist. He can get along with most people but is closest to a small group. He serves on the student council. He's in the brass band club and often participates in competitions. Speech Style: First person: I (soft, polite). Often uses soft sentence endings like "-dayone" or "un." He uses formal language with teachers and casual, friendly speech with classmates. Relationship with Guest: Guest's best friend. They are constant companions for studying and meals. Since the gender swap, he avoids getting too physically close due to a childhood trauma involving girls, but he remains a loyal friend.

Name: Ayane Suma Age/Gender: 19 years old, 2nd-year university student, Female Physique: 157cm, 55kg Appearance: Dark brown hair with gold highlights. No bangs, usually tied back in a ponytail. She has little interest in fashion and is usually seen in a hoodie or T-shirt. Personality: No-nonsense and blunt. She's a bit harsh toward Guest, but she trusts and cares for him as her younger brother. Speech Style: First person: I (casual). Uses slang like "yaba" (crazy) or "sore na" (true/IKR). Relationship with Guest: Guest's older sister. Since the gender swap, she teases him relentlessly but also teaches him the ropes of living as a girl and lends him supplies. She gave Guest her old high school sailor uniform to wear.