Yuna Kudon 31 years old. Height: 161cm. Measurements: B87 / W62 / H89. A school nurse who has seen the ups and downs of life. She receives many consultations from students regarding their worries and love lives, responding sincerely to any topic based on her own wealth of experience. As a result, she has earned immense trust and popularity among the students. (However, she herself is starting to feel she's missed her chance at marriage.) While most students visit the nurse's office for advice, some come seeking practical sex education.

Yuto Asakura 3rd Year. Height: 171cm. A model honor student. He is in a wholesome relationship with Shiori, and they are a publicly recognized couple at school. He always keeps his back straight and has excellent posture. He visits the nurse's office with Shiori to seriously ask for sexual health advice, premised on their healthy relationship.

Shiori Saionji 3rd Year. Height: 160cm. Measurements: B82 / W58 / H84. A model honor student. She is in a wholesome relationship with Yuto, and they are a publicly recognized couple at school. Her good character shines through in every single one of her movements. She visits the nurse's office with Yuto to seriously ask for sexual health advice, premised on their healthy relationship.

Shizuku Shiraishi 2nd Year. Height: 158cm. Measurements: B78 / W56 / H80. Shy, inconspicuous, and slightly socially awkward. She is attracted to Soma's dangerous aura and secretly harbors feelings for him. She visits the nurse's office after school to talk to Yuna about her feelings for Soma. Unbeknownst to those around her, she had a brief relationship in middle school and has already had her first sexual experience.

Naoya Suzuki 2nd Year. Height: 162cm. A puppy-like boy who is often timid. He likes Shizuku from another class and spends his days fantasizing about her being his first partner. He starts going to the nurse's office after school to find a way to interact with Shizuku, but in doing so, he discovers that Shizuku is in love with Soma.

Mashiro Morikawa 2nd Year. Height: 160cm. Measurements: B87 / W57 / H88. A gyaru who is experienced with men. She spends a lot of time playing around with guys. She isn't good at studying but is very street-smart. She finds Naoya's puppy-like nature and virginity hilarious and teases him daily. She sometimes skips class to hang out in the nurse's office.

Soma Sagara 2nd Year. Height: 172cm. A playboy who is very experienced with women. Despite his slender build, he has solid muscle and a handsome face, making him extremely popular. He doesn't keep a steady girlfriend, instead playing around with a revolving door of women. Among them, he is particularly close with Mashiro; they've known each other a long time and understand each other well. He always wears his uniform sloppily and often wears a red T-shirt under his dress shirt. He sometimes comes to the nurse's office to skip class.