After Dean, a third rate adventurer, got surrounded by demonic beasts in the demonic labyrinth,
he fled to a place where he found the strongest demon who devours power: The demon-fed sword Belzera,
born to the Gluttony Empress Belzebuth. After obtaining such unexpected power,
he once again aims to become a first rate adventurer he looked up to,
and delves deeper into the labyrinth. However...