Supernatural, Action, Adventure, Shounen, Drama, Historical

An order has been sent out to hunt down the existence of an Asklepios, a Greek demon god of medicine, whom the Church believes is practicing unorthodox methods. A member of armed force group assigned to this mission by the name of Luca encounters two kids who saved him from an injury he faced during a brawl. Who are these kids and can they help out Luca with his personal reason for doing this assignment?