Kogoro and Conan are taken by Ran and Sonoko to a Rooster Festival. Ran and Sonoko sneak off to have their love fortunes predicted. Sonoko reads Ran's fortune which strongly suggests her to be feminine and avoid mannish conducts. Sonoko is then robbed by a man wearing a hyottoko mask who flees with her purse towards Ran. Ran, hesitant by her love fortune, does not incapacitate him with karate and allows him to escape. Kogoro explains the man has been dubbed as the Rooster Man and is a serial robber at Rooster Festivals. Ran and Sonoko takes Conan with them to visit the festival again to have their love fortunes retold. A woman's scream is heard and they discover that the Rooster Man was spotted and stabbed a man before escaping. Before losing consciousness, the stabbed man, Shiro Masuko, tells Conan it is not rooster but saru (猿, lit. monkey) and shows him nine fingers. Conan investigates the backpack left behind by the Rooster Man and discovers all the possessions stolen by him.