Kimito Kagurazaka is a commoner with a fetish for men's muscles—or at least that's the lie he must keep telling if he wants to keep himself out of trouble at the elite all-girls school, Seikain Academy. Kidnapped by the school under the assumption that he prefers men, Kimito is made to be their "commoner sample," exposing the girls to both commoner and man so that the transition to the world after school is not jarring. Threatened with castration should his sexual preferences not match the school's assumptions, Kimito keeps up the facade to protect his manhood. But there are eccentric individuals around every corner who begin to make Kimito's life even more difficult. Among them are Aika Tenkuubashi, a social outcast who blurts out whatever comes to mind; Hakua Shiodome, a young genius; Karen Jinryou, the daughter of samurai who is obsessed with defeating Kimito; and Reiko Arisugawa, the perfect student who has delusions of marrying Kimito. Along with the commoner himself, these four girls make up the Commoner Club, which attempts to teach the girls more about life outside the school, while Kimito gradually learns about the odd girls surrounding him.

Hacka Dolls are AI that scan a person in order to tailor news recommendations and information to their users. These widespread, personalized robots have served many citizens, from government officials to professional sports players. A severe drop in quality leads to the production of three substandard Hacka Dolls. Due to their personality defects, they are sent to Earth, tasked with advancing humanity in whatever way they can. Whether it be encouraging a fujoshi to sell a doujinshi at Comiket or performing in an idol group, the three dolls will complete any task as long as it abides by their moral compass. Despite their shortcomings, they take their mission very seriously and always try their best to assist everyone with incredible enthusiasm.

During the summer of her freshman year of high school, Yuzu Aihara's mother remarried, forcing her to transfer to a new school. To a fashionable socialite like Yuzu, this inconvenient event is just another opportunity to make new friends, fall in love, and finally experience a first kiss. Unfortunately, Yuzu's dreams and style do not conform with her new ultrastrict, all-girls school, filled with obedient shut-ins and overachieving grade-skippers. Her gaudy appearance manages to grab the attention of Mei Aihara, the beautiful and imposing student council president, who immediately proceeds to sensually caress Yuzu's body in an effort to confiscate her cellphone. Thoroughly exhausted from her first day, Yuzu arrives home and discovers a shocking truth—Mei is actually her new step-sister! Though Yuzu initially tries to be friendly with her, Mei's cold shoulder routine forces Yuzu to begin teasing her. But before Yuzu can finish her sentence, Mei forces her to the ground and kisses her, with Yuzu desperately trying to break free. Once done, Mei storms out of the room, leaving Yuzu to ponder the true nature of her first kiss, and the secrets behind the tortured expression in the eyes of her new sister.

College student Miyako Hoshino is quite shy around other people. She mostly spends her time in her room making cosplay outfits. When her fifth-grade sister Hinata brings her classmate Hana Shirosaki home, Miyako instantly becomes captivated with Hana's cuteness. Miyako tries to do various things, ranging from making Hana wear cosplay dresses to giving her sweets. This gives Hana a bad impression of her at first, but Miyako will do anything to grow closer to the angel who has descended before her.