Buso Renkin

Homunculi-artificial beings created long ago by European alchemists-hide among humans, preying on the unsuspecting. The only weapons capable of destroying them are called Kurogane, which take unique forms based on their wielders’ instincts, manifesting as special abilities known as Busou Renkin. One evening after school, Kazuki Mutou stumbles upon a girl under attack by a homunculus. When he tries to help, she ends up saving him instead, shattering his naive understanding of the world. The girl, Tokiko Tsumura, reveals she accidentally implanted a Kurogane inside him. Now unwillingly pulled into the battle against homunculi, Kazuki must leave his carefree life behind to protect those he loves.