Naozumi Tsuchida (土田直純)Tsuchida-sensei is the only male teacher at Hanamaru Kindergarten, who started teaching in the school after graduation. At first, he was seen as unreliable, but as time passes by, he gets the hang of being a teacher. He is liked by Anzu, but he does not return his affection back to her. He has a crush on Nanako Yamamoto, his colleague. Sakura called him Tsuchi when they were classmates (and still does), so Anzu does as well. He is a game otaku and plays until late at night, often resulting in him being late for work at the kindergarten. He teaches the students of first-year Sakura Class. He is nicknamed "breast man" because of his habit of looking at girl model magazines and often staring at Yamamoto-sensei's chest.
Near the end of the manga, the children at the kindergarten help him muster the courage to confess and he begins a relationship with Yamamoto-Sensei.