The novel opens with a conversation between sano and sanjo about the upcoming milestone of snoka's 18th birthday. . They're planning to celebrate together, but they're worried about what they'll do on the day of the big event. They decide to bake a cake instead, but it's not a good idea, since the oven isn't working and the batter is too thick. They don't know how to make the cake, and they decide to dress up as nurses in order to make it look like a real party. They also worry about what's going on at home, since they'd have to tell rikako about the cake's ingredients if they were to tell her about it. They worry about how much time it'll take to bake the cake and how long it will take them to get home from work. Finally, they decide not to bake at all, and decide to just watch a movie instead.