The Pretty Boy Detective Club, a covert group, is reputed to be the source of many of the problems occurring at Yubiwa Academy, although they are not officially recognized or compensated for their efforts. Mayumi Dojima, a second-year student, seeks their assistance in locating a star she saw a decade ago but ends up with more than she bargained for. The discovery of a mysterious entity dubbed the Twenties changes everything, as Mayumi's future hangs in the balance, and time is running out for the Pretty Boy Detective Club to unravel the enigma of the Dark Star.
