Pitch-Black Infatuation novel was written by Rokakoen and is the second volume of the Sasaki Agency series.

Toshihiko is a cram school teacher and, by all accounts, a very handsome young man. But his life takes a sudden turn when a strange woman starts stalking him. Hoping to solve his problems, he seeks out the Sasaki Investigation Agency. Meanwhile, a bizarre urban legend starts making the rounds among the local elementary schoolers.