Isobe (磯辺) is an annoying classmate of Nanami's, who enjoys calling attention to her poverty. It is also hinted that he picks on Nanami because he has a crush on her.
Isobe likes to make fun of her being poor and he claims he would never date Nanami. However, his feelings are shown when he sees Nanami with Tomoe in the ice cream parlour, looking for Kotarou and he becomes concerned about her because Isobe says Tomoe looks "sketchy".
He also is curious about why she isn't attending class and starts to harass and humiliate her. Although, he becomes scared when Tomoe threatened him not to lay a finger on Nanami. Then, Isobe claims he was only messing around. Paralysed in a state of shock Nanami yells at Tomoe to stop picking on every human he sees and to a frozen Isobe not to pay attention to Tomoe (who is also frozen because Nanami yelled in his ear).
When Isobe tries to bet if Nanami will return back to school, his friend asks him why he keeps pestering and wonders is it because Isobe has a crush on Nanami; Isobe starts to hysterically laugh but also blushes.
When Nanami is sick and can't attend school, she makes Tomoe go to school disguised as her. This resulted in Isobe blushing deeply and dumb struck by her improved appearance' (which is due to Tomoe being disguised as her).