(from ebookjapan):

Shindo, a self-proclaimed playboy salesman, is approached by a beautiful woman who is drinking alone at a club. Shindo is thrown into a tizzy by the beauty, who guesses his age, personality, occupation, etc. The beauty tells him not to approach her until he solves the riddle, "Who sits on the sphinx with the chair?"

Shindo is swept along by the pace of the beautiful woman, and is told by her not to speak to her until he solves the riddle of "Who sits on the sphinx?" Shindo tries to solve the riddle with the help of a strange card given to him by the beautiful woman...?