Aiko meets a boy, and Spank encounters his pet dog, a female named Anna. Spank falls in love with Anna at first sight. One day, a boy named Shima Shō transfers into Aiko's class. He is a violin prodigy. Then, on another day, Seri becomes upset that Shō won't come to her birthday party, so Aiko goes to talk to Shō about it. However, he says, "I'm not going," leading to a fight between him and Aiko. Aiko becomes furious and further forbids Spank from going to Shō's house, which deeply shocks Spank. But on that very night, Anna goes missing...