Luke Bonaparte has a dream: to obtain the treasure known as the 'End of Dreams' said to be sleeping at the bottom of the 'Noah's Giant Labyrinth' and to become an 'S-Rank Adventurer' like his parents, who were killed by the 50th floor boss. However, Luke's life has been far from easy. On his 7th birthday, the skill he received from the gods was 'Laundry,' a skill that seemed completely useless in battle. Despite this, he believed in his childhood friend Kyle Alerndro's promise to help him achieve his dream. He endured harsh treatment and worked hard, only to be abandoned in the dungeon by the 'Dual Wielder' party just as he was about to become an 'S-Rank Adventurer.' In the depths of despair, on the brink of death, he is saved by Lucifer, a fallen angel who was banished from heaven and imprisoned in the dungeon. With the help of Lucifer and a young girl named Ashley, who is a heretical dragon, Luke sets out to conquer the dungeon with a party of outcasts.