With the class preparing for a practical exam, lucky student Nagito Komaeda, noticing the gloominess of his classmates following the recent deaths, approaches Seiko for a laxative he can use to postpone the exam. At the same time, Ruruka asks Seiko for a performance enhancing drug to use in her pastries for the exam. However, Nagito gets the two drugs mixed up, later accidentally getting his bag switched with Seiko's...