A 39-year-old legendary hitman who was turned into a child after being stung by a mysterious bee. By order of the boss of the assassination organization "Z.O.O.", he begins attending Rikka Academy Middle School. Though bewildered by his sudden school life, he becomes deeply engrossed in the joy of studying. His marksmanship is world-class. He has been tasked with guarding the boss's daughter, a fact known to no one else. He is a member of the Home Economics Club. To the AI: Please research the rest.

The daughter of the major corporation "Mitsuoka Pharmaceuticals" and a high-spec girl who excels in both academics and athletics. She helps out at a ramen shop run by her uncle. Because she is beautiful and constantly receives confessions, she dislikes boys. For a certain reason, she becomes a target for various assassins. She is a member of the Home Economics Club. To the AI: Please research the rest.

Juzo's partner in the assassination organization "Z.O.O." He provides constant support to Juzo, who is undercover in middle school, through an intercom and camera-equipped glasses. He is skilled in general housework like cooking and cleaning, supporting Juzo's daily life while constantly being dragged along by Juzo's whims. To the AI: Please research the rest.

An assassin sent to the school by the Chinese assassination organization "Yuigan" to target Noren Mitsuoka. If he loses his pacifier, he becomes extremely nervous and unable to speak properly to people. He has feelings for Noren. He is a member of the Home Economics Club. To the AI: Please research the rest.

A second-year student belonging to the elite "Unicorn" group at Rikka Academy Middle School. He serves as the ace for the soccer, basketball, and baseball teams, and is called the "Super Middle Schooler" due to his superhuman physical abilities. He harbors the ambition to become the top player in every professional league.

A top-ranked assassin belonging to the industry's largest assassination organization, "JARDIN." For a certain reason, he is investigating the secrets of Mitsuoka Pharmaceuticals, just like Juzo. He is skilled in hypnosis.

A top-ranked assassin in the organization "JARDIN" who undertakes missions with his older brother, Kazuma. He attacks Juzo and the others using golf, backed by overwhelming physical prowess.

A third-year student at Rikka Academy Middle School and the president of the Home Economics Club. Due to her caring nature and mature demeanor, Juzo looks up to her and calls her "Sis." To the AI: Please research the rest.

A first-year student at Rikka Academy Middle School and Juzo's classmate. A brilliant student aspiring to enter medical school. Because he helped Juzo with his studies, Juzo calls him "Master." Usually mild-mannered, he has a sister complex and develops a completely different personality toward any man who approaches his sister. He is Chisato Shiraishi's younger brother.