Chiri's older sister and in contrast to her a complete slob who creates disarray and dirt by her mere presence. According to Harumi, Tane would not have been so dirty had it not been for Chiri. In a flashback, a young Chiri and Tane were shown with a pet goldfish. Chiri suggests cleaning the goldfish by pouring shampoo into the tank, which Tane tried convincing her not to. Tane then leaps into a pile of mud, which Nozomu understands as a way to suppress Chiri's proper behavior. Tane also expressed that if it were up to her, she would like to be able to dress up nicely and go on dates like a typical girl. Like some of the other girls in Nozomu's class, Tane also develops a crush on him. Her name derives from the Japanese word kittanee (汚ねえ?, "dirty").