Monster Strike: Rain of Memories

A year before Ren arrives in Kaminohara, Akira Kagetsuki moves there carrying a private grudge. His sister was badly hurt in a Monster Strike battle, and he has turned that pain into a ruthless style built on reading his opponents and crushing them before they can strike back.

Haruma notices more than Akira's cold exterior after a chance meeting reveals an unexpected kindness. Convinced that Akira is the missing fourth member his team needs, Haruma asks Aoi and Minami to give him a chance. Their decision becomes the beginning of a bond that will shape all four of them, while Akira struggles to decide whether revenge is the only thing he deserves to carry forward.