Battle Rabbits Vol 1

Kokuryuu Kaguya was only a little boy when he witnessed his father murdered by demons. Despite no one believing him, he'll never forget that moment... Years later, Kaguya is struck by a mysterious light, and finds himself at the receiving end of a monstrous attack. A skilled warrior adorned with bunny ears rescues him, and sends Kaguya down the path of becoming the Earth's newest defender--as a Battle Rabbit!