The short begins with Rei, dressed in the penguin Speedo Nagisa lent him, getting ready to jump from his diving block at the edge of the pool on the Iwatobi High School campus. Just as he dives, however, he suddenly wakes up during class and ends up rattling his desk which surprises and silences the entire classroom. Surprisingly, Rei had been daydreaming all along. Just behind him, Nagisa bursts out laughing to which Rei frantically yells at him to stop. (thetvdb.com)