A gym teacher at the girls' school. In the girls' first year of high school, she is the homeroom teacher of Class 5. During their last two years, she is the homeroom teacher of Class 2. An old high school friend and rival of Yukari, they have a juvenile, exasperating, but funny relationship with each other; Yukari relentlessly insults and freeloads from Nyamo, but Nyamo gets her digs in, too. "Nyamo" is a nickname from her student days, but Yukari calls her that, and so does Tomo. Other students call her Kurosawa-sensei. Whereas Yukari appears to be an older version of Tomo, Nyamo resembles Yomi (more in personality than looks) and the two teachers' odd relationship is similar to the one that Tomo and Yomi share.

Popular with the students, Nyamo is nicer, less obnoxious, and far more in control than Yukari. Yukari often teases her about her past romantic relationships and that she is a "stupid P.E. teacher." During one of the summer trips the girls take together, Nyamo gets very drunk (usually, Yukari is prone to this behaviour; as a matter of fact, Nyamo drank specifically to keep the alcohol away from Yukari) and tells the girls all about the birds and the bees, which embarrasses Sakaki and confuses Chiyo, but impresses the other girls.

In addition to teaching her homeroom class and P.E., Nyamo is the coach/advisor of the women's swim team. Kagura calls her "Coach" and holds her in very high regard. The fact that students tend to come to her with their problems is yet another source of Yukari's jealousy, as well as the fact that she is generally more "together" and better-disciplined.

Unlike Yukari, Nyamo is able to maintain an apartment of her own. She also owns and drives a blue Toyota Vitz 5-door. She is very sensitive to comments about her love life, which has evidently provided Yukari with an endless supply of blackmail material and points at which to rib her. One of these apparently involves a "love letter" from high school, which Yukari loves to dangle over her head. Still, she is quite devoted to teaching and at one point turns down a job offer that would have given her far greater income and prestige.