Klaus, near death from a high fever, encounters a goddess who grants him the unique skill 'Incubation'. Upon regaining consciousness, he finds himself surrounded by his parents and sister, Celia. After a series of events, Klaus becomes an adventurer and discovers a large egg deep within a forest. Upon hatching it, he finds a phoenix! A magical contract is automatically formed, granting him the ability to use some of the phoenix's powers. As Klaus's true abilities with 'Incubation' are revealed, he gains recognition among adventurers and eventually attracts the attention of the kingdom.