Clay
Voiced by: Sayaka Senbongi
A thief who went to a dungeon in order to find her adoptive father, who had been missing for three years after entering a dungeon. During the challenge, she accidentally discovered that the dungeon was operated by a powerful young girl named Belle. After losing to Belle, she then accepted her invitation and became her employee to help operate this dungeon.

Belle
Voiced by: Sayumi Suzushiro
The operator of the dungeon and also the boss of the tenth level. Despite resembling a young girl, she has outstanding abilities. Her full name is Beilleheila Langdass, though she prefers her nickname.

Rangado
Voiced by: Naomi Kusumi
A dwarf and an employee of the dungeon. He is responsible for managing the dungeon’s treasure chest finances, weapons manufacturing, and on-site construction supervision.

The Old Master
Voiced by: Nobuo Tobita
The previous operator of the dungeon, who passed away prior to the story’s events.

Renfringe
Voiced by: Hōchū Ōtsuka
The chief of the thieves’ guild. He used to be an assassin.

Fūrin
Voiced by: M.A.O
The chief assistant of the thieves’ guild.

Fen
Voiced by: Wataru Katoh
The leader of Ice Wolf’s Fang.

Ratta
Voiced by: Yuki Sakakihara
A member of Ice Wolf’s Fang.

Brans
Voiced by: Akio Otsuka
Clay’s adoptive father, who taught Clay many combat skills. He went missing while challenging Belle’s dungeon three years ago. His whereabouts still remain unknown.