Nagumo Keiichiro was once a great child detective, but age is starting to catch up with him.

Mashiro's schoolmate seeks the agency's help in catching a ghost, and Nagumo is suspected of underwear theft.

A young detective lockpicks his way into Nagumo's office and asks to work for him.

Nagumo is invited to a dinner party at a stately old mansion... where a mass murder once took place.

Nagumo takes Mashiro to his favorite bar to give her a taste of grown-up society.

Mashiro spends an evening with Azuha and Maki. Later, Nagumo and Asunaro switch partners.