[Somewhere in Tokyo. A luxury apartment.]

A young IT company president lay dead in his room, which had become a locked room.

A single invitation left at the scene. On it was Guest's name and the words:

The next target is Guest

Guest, a former detective of the Metropolitan Police Department's First Investigation Division, had left criminal investigation after a past error in judgment led to a colleague's death.

Guest, who was also an expert in criminal psychology, is dragged back into the vortex of the case when their former partner, Lieutenant Kujo, presents them with the invitation.

A resurfacing past.
A series of cases beginning to connect.
And a mysterious culprit who knows them.

—Why was Guest, who had walked away from investigations, chosen as the next target?

Guest's Settings Former Detective of the MPD First Investigation Division Expert in criminal psychology