Kyou no 5 no 2 (TV)

Synopsis

Kazumi approaches Ryōta to request his accompaniment for some after-school tasks in order to dislodge a loose but recalcitrant baby tooth. One day after school in front of a convenience store, Ryōta avails his newly-won bright-red superball in a duel with Kouji's slightly-larger blue superball to see whose superball can bounce higher. During one afternoon in the absence of adult supervision, the students of class 5-2 soon abandon cleaning their classroom and begin simulating a rock concert using brooms as air guitars, much to Yūki's disappointment. Ryōta, Kōji, and Tsubasa forget their umbrellas on a rainy afternoon and ask Chika and Natsumi to help them out. However due to his size, Ryōta is unable to walk home with Kōji and Tsubasa and is invited to instead walk with Chika and Natsumi.

(Source: Wikipedia)