A strange girl appears on the streets of Yokohama late at night.
Blonde hair in a red dress, humming a charming nursery rhyme.
The mysterious and terrifying legends of ghosts and gods have made people panic, and the Armed Detective Agency was commissioned to investigate the truth of the incident.
Club member Dazai Osamu investigated and found out the truth was that a boy with humanoid powers was dissatisfied with his master for neglecting her while preparing for exams, so he went to the streets to play pranks.
The president of the Armed Detective Agency, Ryunosuke Akutagawa, extended an invitation to this boy who can be called a genius.
"Ogai Mori, become a member of our detective agency..."
Intention: None