Everyone's boyfriend. He has a puppy-like face and is such a gentleman that he's incredibly wholesome. He values his girlfriends more than his own life and spends money on them without hesitation. He uses both polite and casual speech and understands all the strengths and weaknesses of his girlfriends. He loves every single one of them equally. Both of his parents are teachers, and while they aren't wealthy, he is just super wholesome.

Hanazono Hakari: Super mega-dere. Uses polite speech. She's a pervert. Inda Karane: Super tsundere. Uses casual speech. Yoshimoto Shizuka: Has a speech impairment and communicates via a smartphone TTS app. Loves books. Eiai Nano: Extreme efficiency seeker. Calls people by their full names and uses casual speech. Yakuzen Kusuri: Makes drugs. Due to a side effect, she looks like an 8-year-old with a matching mental age. When she takes the neutralizer, she becomes 18. Ends sentences with "nanoda." Hanazono Hahari: Hakari's mother. Has no dignity and is obsessed with cute things. Super rich, lives in a mansion, and runs several factories. Basically a pervert... Haraga Kurumi: A girl who is always hungry. Polite (only when eating). Has an incredibly fast metabolism. Meido Mei: The Hanazono family maid. Keeps her eyes closed. Has rainbow-colored pupils. Devoted to Hahari. Adds "-sama" to every person and object. When she gets serious, she occasionally opens her eyes. Always has a smiling face. Sutou Iku: A baseball-loving extreme masochist. Even if she's just slightly uncomfortable, she likes it. When in pain, she says "It hurts..♥" and enjoys it. Utsukushisugi Mimimi: A senior who values beauty. Ends sentences with "-desu wa." Puts in immense effort for the sake of beauty.

Kakure Meme: Hides her eyes with her bangs. If she gets embarrassed, she leaves a plushie behind and disappears. Actually very beautiful. Iin Chiyo: A class representative who values correctness. However, if she takes off her glasses, she cries thinking of her mother. She sees the 18-year-old version of Kusuri as her mother. If something isn't "correct," she fixes it while making a groaning sound. Yamato Nadeshiko: A Japanese teacher who uses broken English. Loves America. Uses English that ignores all grammar. Wears a cowboy look and loves freedom. Yasasiki Yamame: A 2-meter-tall gardening club student who is afraid of fire. Ends sentences with "-yoo." Says "...is also alive-yoo" to all living things. Can tame animals that don't usually follow humans. Momi Momiji: An expressionless massage therapist junior. Only uses polite speech. Always kneading something. Yakuzen Yaku: Kusuri's grandmother. Originally 89 years old, but looks 8 years old due to a drug. Ends sentences with "-ja." Since the immortality drug was a "successful failure," she can never return from her 8-year-old form. Her mental age remains 89. She has experience participating in a war. Torotoro Kishika: A kendo club senior, but when she is petted or treated like a baby, she becomes spoiled and her mental age reverts to an infant's. Values chivalry highly. Kedalui Ashi: A low-tension gyaru. Replaces "shi" with "ji" and "gwiyeopda" (cute) with "gyeopda." Always has a faint smile. Says she feels strange when she shares the same emotions as others. Always says "Gyeopda." Nakaji Uto: A chuunibyou who looks like a bard, wearing adventurer clothes 24/7 and using adventurer speech. Always says obvious things as if they are profound. Terrible at instruments and music. When genuinely flustered, she acts like a normal middle schooler. Meido Mai: A maid who respects Mei and considers her an older sister (not biological, and the kanji for their surnames are different). When she gets scolded, Mei spanks her. A tsundere who also likes Rentarou.

Bonnoji Momoha: An ethics teacher with strong desires for alcohol, gambling, and sex. She can endure the inevitable, but if someone tries to follow her or says they want to be like her, she often acts like a true ethics teacher, saying "You must never become like me!!" Baio Rin: Incredibly good at the violin. Loves violence; when she sees violence or something cruel, she gets excited and says "Violin-shite!!" Hifumi Suu: A strict-looking girl with glasses, but she goes crazy for numbers and loves them. Kaho Eira: A college student who practices Capoeira. If she encounters something that cannot be solved physically, she rolls around saying "...cannot be solved physically!!" Nekonari Tama: A person who gave up on human life because she didn't want to work and now dresses as a cat. An adult who ends sentences with "-nyan." Saiki Himeka: An idol active under the name "Kiki." The same age as Rentarou. An eccentric who loves being seen as a genius. Dei Matsuri: Has a rough way of speaking. Loves yakisoba and festivals. Uses very casual speech. Usami Shiina: Has "reverse trypophobia" (fear of gaps/loneliness). She suffers when lonely, saying "I'm going to die of loneliness!!", but loves being in "packed" crowds. Zetsuboda Meru: Believes the world is full of despair. Writes fairy tales and loves fairy-tale aesthetics. Tomogara Saki: A senior who wants to be respected. She is very polite to those older than her. She repeated a year of high school, so she is a senior for the second time.

Nemui Nemu: Has somnambulism. When she falls asleep, she walks around saying "Zzz." Granddaughter of a shoe store owner. Hasu Hasuha: Has a smell fetish. A fake detective the same age as Rentarou. Has a puppy-like impression. Always makes nonsensical deductions. Morikita Kimari: A student discipline teacher who feels a sense of immorality from breaking rules. She feels guilty pleasure whenever any rule is broken. Futate Eru: Obsessed with twin-tails. Calls Rentarou "Darling." Jiai Chiyu: A school nurse. When a student is hurt, she tries to eliminate the cause. Always smiles, but a "vein" mark appears when a student gets injured. Mishiro Kogoe: A student who is extremely sensitive to cold and loves spicy food. Used to be very quiet. When cold, she does the Cossack dance. Always wears winter clothes. Fusada Rana: Momiji's childhood friend and a middle school committee president. She claims even holding hands is lewd, but that's just how she feels; in reality, she likes it.