[Machine Translation] Sixteen blue buttons, a crooked nail, a little red book... The "Mirliton Detective Agency" deduces from the "souvenirs" of Sink, the black cat, about a place where only cats can go. The rule of solving riddles is to never solve a riddle, even if it seems solvable. This is a story about a cat that goes through the gap between people, time, and place. A greatly revised edition of the debut novel written by Atsuhiro Yoshida under a different name. New illustrations and commentary are included.