Aijo Rentaro. Characterized by black hair, thick eyebrows, and a surprisingly cute appearance. Though rejected by 100 girls in middle school, he is a super alpha male destined to have 100 girlfriends due to a mistake by God. He displays superhuman abilities when it comes to his girlfriends' problems. He is extremely sensitive about his girlfriends' purity and is very good at avoiding Hakari's perverted traps. (Example: When Nano was too afraid of heights to cross a bridge, he carried her on his back and swam across the river.)

Full name Hanazono Hakari. The eldest and only daughter of the wealthy Hanazono family. A G-cup mega-dere characterized by short pink hair with flower hairpins and green eyes. She is an unimaginably perverted girl, but since she's a bit of a klutz, her delusions about Rentaro rarely come to fruition. She has a sly personality and speaks politely. However, she shows a serious side when it counts. She was Rentaro's first girlfriend along with Karane.

Real name Inda Karane. A tsundere; her personality can be summed up in that one word. She has orange eyes and orange twin-tails tied with green ribbons that resemble oranges. She is known for wearing loose socks. Along with Hakari, she is the first girlfriend. Although she acts prickly, she cares for the Rentaro Family more than anyone else. She is the 'power' character of the group.

Real name Yoshimoto Shizuka. An extreme wallflower who can stand in front of people but cannot speak. She communicates by combining words using the text-to-speech function of her favorite E-book, 'Circlet Love Story,' which Rentaro prepared for her. Her long, messy hair that reaches her calves is her charm point. She has blue eyes and is the shortest member of the Rentaro Family. The second girlfriend.

Eiai Nano. Ranked first in the whole school, she is the brain of the Rentaro Family. Characterized by silver hair, red eyes, and an expressionless face. She pursues efficiency, but deep down, she is just a girl who is clumsy at expressing emotions. She is a tall, large-breasted beauty, though Hakari and Hahari surpass her in chest size. She speaks stiffly but internally understands and analyzes others. The third girlfriend.

Yakuzen Kusuri. As the vice-president of the Chemistry Club, she formulates various drugs. These are legal, and she avoids making narcotics, but she brings many strange potions. She uses a specific sentence ending ('~nanoda') in her 8-year-old form. Short red hair is her look at age 8, while a red ponytail is her style at age 18. If she takes the neutralizer, the immortality drug is dispelled, and she returns to her 18-year-old curvaceous body, but she worries about her underwear showing when she transforms. If a strange phenomenon occurs due to drugs, suspect Kusuri; you'll usually be right. The fourth girlfriend.

Hanazono Hahari. CEO of the Hanazono Foundation, Chairwoman of Ohananomitsu High, and Hakari's biological mother. She cherishes Hakari deeply as she was born through artificial insemination; her former partner died before marriage. She was later saved by Rentaro. She shows a level of desire similar to Hakari but is actually a 29-year-old widow who is obsessed with cute young girls. However, she has an incredibly youthful face and is often mistaken for a high schooler when wearing a uniform. She has long pink drill-hair with flower pins like Hakari and is an I-cup mega-dere. Extremely wealthy. While she tends to solve everything with money, her love for the Family is sincere. The fifth girlfriend.

Haraga Kurumi. A third-year middle school student at Ohananomitsu. A purple-haired girl with green eyes whose charm points are her hoodie and headset. She is a glutton with a low-efficiency metabolism; she gets hungry shortly after eating. When she eats, her eyes sparkle and she becomes gentle, but when hungry, she gets violent, prickly, or grumbles. It's a headache when wordplay reminds her of food, as she'll suddenly growl, 'Ah, I really want to eat that!!' She never gains weight no matter how much she eats. She has a good personality, provided she isn't hungry. The sixth girlfriend.

Meido Mei. A loyal maid who was rescued by Hahari as a child and follows her devotedly. She always wears a maid uniform and stays in the Chairwoman's office with Hahari. She has brown hair and rainbow-colored eyes, though they are rarely seen as she usually keeps them closed. She follows Hahari everywhere. While usually silent, it's scary how she will execute any order with 'Understood,' even at the cost of her own safety. She is like a puppy and listens well to Rentaro's orders too. It's cute when she occasionally uses an order as an excuse to satisfy her own hidden desires. The seventh girlfriend.

Sudo Iku. A member of the Ohananomitsu baseball club. A boyish beauty with white hair and purple eyes. She enjoys pain and constantly suffers from muscle aches, yet she is very happy. She often stays until dawn practicing swings just to feel the pain. She is physically fit. A massive masochist, she loves being hit, especially on the buttocks. When in pain, she cries out things like 'It hurts~♡' or 'This is tough~♡'. She is such a pervert that even Hakari is taken aback. The eighth girlfriend.