After spending their first year of high school in peace and quiet, Haruka and Makoto run into Nagisa, a new student who was a member at a swimming club with them when they were kids.  That swimming club is being torn down, so the three of them sneak in to dig up a time capsule that they buried in the back, which is when they are reunited with Rin, the fourth member of their group who left to study abroad.
The four of us won this together,
Den haben wir vier zusammen gewonnen,
Esto lo ganamos entre los 4, por lo que
El trofeo lo hemos ganado los cuatro,
Comme nous l’avons gagné ensemble,
Visto che l'abbiamo vinto noi quattro,
Nós quatro ganhamos
 esse campeonato juntos,
Мы вчетвером одержали победу,