Overview: A series of murders of female pastry chefs occur in Yokohama City near Valentine's Day. Seiya arrives at the scene and suspects that a cake left behind may hold the key to solving the case. On the back of the cake, there is a pattern that looks like an inverted “4” combined with a number of horizontal lines. Momo learns that the two victims are graduates of the same confectionery school, and she becomes increasingly wary, deducing that the patissier who made the cake that was left behind will be the next target of the murder. Meanwhile, Seiya watches as Kyoko makes homemade chocolates, and realizes the secret of the cake at the scene -- it was made by a pastry chef.