Kenka no Gokui 2.

Haru and Shingo’s days remain filled with constant brawls. When a new transfer student arrives, Haru braces for a rival—only to discover the newcomer is Kana’s older brother. While Haru awkwardly tries to get closer to Kana, disaster strikes: she is kidnapped by students from a rival school. United by rage, Haru and the others charge in for a rescue—only to face an unseen threat waiting for them.