Haruko Miura teaches as the homeroom instructor for Norimichi Shimada, Yusuke Azumi, and Nazuna Oikawa's junior high class. Her male students routinely subject her to sexual harassment, mocking and gossiping about her bust size. Their actions escalate to attempts at photographing her underwear, depicted as comedic moments.

She secretly dates fellow teacher Mr. Mitsuishi. Their relationship sparks discussion when Miura wishes to reveal it publicly, and students later witness the couple together, confirming their romance. Professionally, she manages administrative duties like receiving and processing Nazuna Oikawa’s transfer notice, which signals Nazuna’s move due to her mother’s remarriage.