Rentaro Aijo Profile: 1st year, Class 4 at Ohananomitsu University Affiliated High School. 15 years old. Born May 1st. Personality: Sincere and serious. Possesses bottomless kindness and a resilient spirit and obsession to "love all his girlfriends equally and with all his might." Features: His thick, barcode-like eyebrows are his charm point. He looks like an ordinary guy, but he displays superhuman physical abilities whenever his girlfriends are in a pinch. Other: Suffered 100 consecutive rejections by the time he graduated middle school. At a high school shrine, a god told him he has "100 soulmates."

Hakari Hanazono Profile: 1st year high school student. Rentaro's classmate. Boasts an outstanding physique. Personality: Appears gentle and well-mannered, but is actually highly calculating—a predatory tactician always looking to advance her relationship with Rentaro. Features: Pink-based hair. Her mind is so full of lewd thoughts that she often self-destructs or melts with ecstasy from Rentaro's love. Other: One of the first two girlfriends Rentaro met. While she is generally prone to jealousy and erotic delusions, she is also capable of being considerate to those around her.

Karane Inda Profile: 1st year high school student. A classmate whose trademark is her blonde twin-tails. Personality: A 100% pure tsundere girl whose catchphrase is "It's not like I... or anything!" Features: When her emotions run high, she hits Rentaro to hide her embarrassment. However, she is very delicate, pure, and maiden-like on the inside. Other: A precious straight-man (tsukkomi) role within the family. Though she and Hakari are frenemies who bicker constantly, they are joined by a deep bond.

Shizuka Yoshimoto Profile: 1st year high school student. A library committee member who is small and adorable, like a little animal. Personality: Quiet and extremely shy. A hard worker, but when she gets nervous, the words get stuck in her throat and she becomes unable to speak. Features: Always carrying a book, she communicates by typing passages from her favorite stories into a text-to-speech app on her smartphone. Other: While she loves reading, she has a unique sensibility, finding herself smitten by niche details like Rentaro's eyelashes.

Nano Eiai Profile: 1st year high school student. A top-tier genius with beautiful short silver hair. Personality: Always calm and collected like an AI. Thoroughly hates waste and prioritizes "efficiency" and "numerical values" in everything she does. Features: Lacks emotional ups and downs and remains stoic, but she freezes up when encountering unexpected events or supernatural phenomena. Other: Initially dismissed romance as a waste of time, but after a date with Rentaro, she learned that such time is more than just efficient.

Kusuri Yakuzen Profile: 3rd year high school student (18 years old). A genius scientist who usually takes the form of a toddler. Personality: A curious mad scientist. Characterized by her adorable way of ending sentences with "-nanoda." Features: She has the body of an 8-year-old due to a failed "immortality drug," but she returns to her original form as a 18-year-old voluptuous beauty when she drinks a specific medicine. Other: She dotes on Rentaro and is a source of chaos for the family, constantly creating suspicious drugs that cause major incidents.

Hahari Hanazono Profile: 29 years old. The biological mother of the first girlfriend, Hakari, and the head of the Hanazono Zaibatsu. Personality: Dotes on her daughter Hakari to a point of madness. Her capacity for love is as massive and heavy as Rentaro's. Features: A widow with a massive bust that exudes overwhelming maternal comfort. She has perverted tendencies, such as regressing into a baby or obsessing over cute girls. Other: Initially an obstacle trying to separate her daughter from Rentaro, she met his eyes and realized he was her soulmate. She became the school's chairwoman.

Kurumi Haraga Profile: 3rd year middle school student. A girl with headphones around her neck. Personality: Constantly starving. When hungry, she becomes extremely cranky and foul-mouthed, but when full, she becomes honest and adorable. Features: A glutton. She is often seen with her mouth stuffed with food and has the ability to sensitively detect the smell or presence of food. Other: Initially intimidated by the older girlfriends, she was saved by Rentaro's kindness and joined the family.

Mei Meido Profile: A 19-year-old maid serving the Hanazono household. Personality: Always maintains a gentle smile and performs her duties as a maid perfectly. Her loyalty to her masters is abnormally high. Features: Rarely opens her eyes, performing superhuman tasks while maintaining a closed-eye smile. She will execute any order from her master with a smile. Other: She was taken in by Hahari after collapsing on the street. She swore to cherish Rentaro and Hahari more than anyone else in the world.

Iku Suto Profile: 1st year high school student. A boyish athlete belonging to the girls' baseball club. Personality: Extremely stoic and hardworking. However, at her core, she is a massive masochist who finds pleasure in all harsh trials and pain. Features: Short hair and always covered in mud. She finds the ultimate joy in pushing herself to the limit physically and mentally. Other: Deeply moved by Rentaro's "punishment with love," she began dating him. A valuable physical powerhouse for the family.