Yuno and Miyako's teacher, Yoshinoya, has to finish the remaining school works during the summer break under the Principal's watch. However, she keeps slacking off from her work as she takes photographs of herself, which will be used for the postcards that she will be sending out to the students. When Natsume discovers Yoshinoya in the school, Yoshinoya asks her to put some of the postcards in the mailbox of Hidamari apartment...