Nor is the third son of a baronet. He'd planned to become a librarian, but after his place was stolen by a viscount he instead aimed to attend the Hero School. He happened upon the "Secret Dungeon - A Neverending Labyrinth", and inside discovered the legendary hero Olivia, trapped. She passed on her unique skill to Nor. After graduating he becomes an adventurer, completing assignments and hunting evil spirits in the labyrinth to level up. He's saving up money...

Emma has been Nor’s friend since they were young. She’s the daughter of the baronet family Brightness. Emma managed to get a job as a librarian, but upon learning of Nor’s decision to aim for the Hero School, she immediately quits her job and decides to join him. She becomes an adventurer as well and forms a duo with Nor.

Rola’s the receptionist at Odin Adventurer Guild, and she is also in charge of Nor.

Olivia is an excellent female adventurer who was active 200 years ago. She found the neverending labyrinth just by chance, but got trapped on the second floor. Despite the time that passed, she never died but remained in the labyrinth, with her limbs tied up by chains and her eyes closed. When Nor finds her, she passes on her unique skill to him, and in return she asks him to become her conversation partner as well as for him to call her master. Because of the trap she’s caught in, she’s unable to move one of her eyebrows so she usually talks to Nor through telepathy.

Luna is an elf working in a church, referred to by many as a saint. She’s Rola’s best friend and a solo adventurer at Odin.

Alice is the only daughter in the Stalgia family, and Nor’s younger sister. She’s extremely attached to Nor.