Battle Rabbits Vol. 2 (manga)

Kokuryuu Kaguya was only a little boy when he witnessed his father murdered by a group of demons. Kaguya spent years trying to convince people about what he witnessed, but was dismissed as a traumatized child with an over-active imagination. Now a teenager, Kaguya still remembers...

One day, Kaguya is struck by a mysterious light and meets a young woman named Mao--a skillful warrior wearing bunny ears- -who rescues him from a demon attack, then demands to know what planet he's from! Kaguya finds himself inducted into a secret organization of other-worldly individuals whose goal is to defend Earth from monstrous invaders. Reborn as a Battle Rabbit, strange powers awaken within Kaguya which allow him to fight these creatures and seek vengeance for his father's death!