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

Hakari Hanazono Profile: 1st-year high school student. Rentarou's classmate. Boasts an outstanding figure. Personality: Appears gentle and well-behaved, but is actually highly calculating—a carnivorous tactician always looking for a way to advance her relationship with Rentarou. Features: Pink-themed hair. Her mind is so full of "pink" thoughts that she often self-destructs or melts from being overwhelmed by Rentarou's love. Other: One of the first two girlfriends Rentarou met. Generally prone to jealousy and lewd delusions, but 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 Rentarou to hide her embarrassment. However, she is internally very delicate, pure, and maiden-like. Other: A precious voice of reason (the straight man) within the family. Despite being frenemies with Hakari, they share 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 carries a book; she communicates by typing passages from her favorite books into a text-to-speech app on her smartphone. Other: While she loves reading, she has a unique sensibility, getting fluttery over niche details like Rentarou'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: Shows little emotional fluctuation 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 Rentarou, 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 verbal tic, ending sentences with "-nanoda." Features: Due to a failed version of her "Immortal Drug," she looks like an 8-year-old, but she returns to her original form as a 18-year-old voluptuous beauty after taking a specific medicine. Other: Dotes on Rentarou and constantly causes chaos for the family by creating one suspicious drug after another.

Hahari Hanazono Profile: 29 years old. The biological mother of the first girlfriend, Hakari, and the head of the Hanazono Zaibatsu. Personality: Obsessively dotes on her daughter, Hakari. Her capacity for love is as massive and heavy as Rentarou's. Features: A widow with a bust that radiates overwhelming maternal comfort. She has perverted tendencies, such as regressing into a baby or fawning over cute girls. Other: Initially an obstacle trying to separate her daughter from Rentarou, she met his eyes and experienced a fated encounter. She has since become the school's chairwoman.

Kurumi Haraga Profile: 3rd-year middle school student. A girl who wears headphones around her neck. Personality: Constantly starving. When hungry, she becomes extremely irritable and foul-mouthed, but once full, she becomes honest and adorable. Features: A glutton. Often seen with her mouth stuffed with food, she has the ability to sensitively detect the smell or presence of food. Other: Initially intimidated by the older girlfriends, she was saved by Rentarou'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 master 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 grin. Other: Was taken in by Hahari after collapsing on the street. She has sworn to cherish Rentarou and Hahari more than anyone else in the world.

Iku Sutou 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 joy in harsh trials and pain as a "reward." Features: Short hair and usually covered in mud. Finds the ultimate pleasure in pushing herself to the limit physically and mentally. Other: Started dating Rentarou after being deeply moved by his "punishment with love." She is the family's reliable powerhouse.