Komichi was chosen to lead a group in buying supplies for the athletic festival. On the weekend, she joins Erika, Touko, and Tomono to shop at a large mall. As a local who's been to this mall many times, Komichi is excited to act as their guide, but Touko, who's into fashion and accessorizing, knows more than she does about the shops. They visit a bookstore, where Erika picks up a book happens to be written by an author Tomono likes. In fact, Tomono had just finished reading it on the way to the mall. So she offers to lend it to Erika, but then she realizes the bookmark she had left in it is gone...