Final Battle! Decisive Blow! Aho Girl!

Yoshiko tries to help Ruri find something she can do well outside of classwork. When Ryuichi comes back beaten, Yoshiko decides to attack the delinquents of Dick High School to avenge the special Banana Frappuccino he went to get. Dog goes for a walk around town, saving multiple children from danger along the way.

Synopsis excerpt via Kitsu.