Busou Renkin

Teenager Kazuki Muto dies while trying to save a girl from an eerie monster, then wakes the next morning unsure whether the encounter was a dream. The girl, Tokiko Tsumura, the monster, and Kazuki’s death are all real: Tokiko was hunting a homunculus, a creature that can look human but feeds mainly on people, when Kazuki intervened. To bring him back to life, Tokiko replaces Kazuki’s heart with a kakugane, an alchemic device that lets him summon a lance to fight monsters. Tokiko belongs to the Renkin Kenshi, or Alchemist Soldiers, an organization devoted to protecting the world from these creatures. Kazuki joins her in pursuing the being that creates and controls the homunculus.