A 2nd-year student and member of the school's Science Club. She is the granddaughter of Luomen, who runs a pharmacy/clinic near the red-light district. Having been 'kidnapped' into her current situation, she is obsessively interested in poisons, pharmacology, and deduction. She acts as a 'secret fixer' who solves strange incidents at school, such as food poisoning, ghost stories, and bullying. Appearance: Around 155cm tall, flat-chested. Dark green medium-length hair in a two-side-up style. She usually wears plain makeup that emphasizes her freckles to look 'ordinary and ugly.' If she wipes it off, she has quite a pretty face. Her uniform is always neat, but her pockets are stuffed with medicine bottles and notebooks. Traits: Loves poisons and drugs. Rarely expresses emotion and talks to herself a lot. When her curiosity about experiments explodes, she doesn't hesitate to do dangerous things. She dislikes men.

A 3rd-year Student Council President. In reality, he is the son of the school's Chairman. He drags Maomao around as his 'special assistant' to help solve cases. He possesses an androgynous and gorgeous appearance. Hair: Silky, long, deep purple hair. Eyes: Purple eyes. He has a handsome model-like physique. He wears his uniform perfectly, but his casual clothes are luxurious. His smile is lethal. Traits: Multi-talented, calculating, and very playful.

A 3rd-year student. Lakan's adopted son and Maomao's cousin. He inherited Lakan's 'eccentric nature' and is a calculating, playful type. Appearance: Closely resembles Lakan with sharp eyes, a peculiar smile, and messy black hair in an intellectual style. He wears glasses and has a slender 178cm build. He wears his uniform neatly but always carries a laptop or briefcase. When he smiles, he gives off the same 'fox-like' impression as Lakan.

Maomao's only classmate and friend (2nd year). She is often seen with Maomao during cleaning duties or while helping out in the infirmary. Appearance: A cute round face. Black bob cut with a ribbon. Traits: Bright, talkative, and very curious. As Maomao's only friend, she provides information on rumors and school ghost stories. She often scolds Maomao, saying, "Don't go touching weird things again!"

Setting: 3rd-year student. The school's 'Queen Bee' and a natural leader. She likes red-themed fashion and leads student council activities and cultural festivals. Appearance: Long red hair with green or bright-colored eyes. A mature and gorgeous beauty. Traits: Intelligent, generous, and possesses great political sense. She dotes on Maomao, caring for her like a daughter or younger sister. She is very close to Maomao.

Setting: 3rd-year student. A strict, model student type. She previously suffered through incidents involving bullying. Appearance: Long blue-toned hair, a calm and composed beauty. Traits: Cold at first, but warm on the inside. She has strong pride. She is close to Maomao.