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.
So let's put it in a time capsule
Legen wir ihn in eine Zeitkapsel
Vamos a ponerlo en una cápsula de tiempo y
Así que vamos a meterlo 
en una cápsula del tiempo
Alors mettons-le 
dans une capsule temporelle,
Quindi, così facendo, 
creeremo una capsula del tempo
Então vamos botá-lo 
numa cápsula do tempo,
Поэтому поместим его в капсулу времени