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.
and dig it up when we're grown up.
und graben ihn aus, 
wenn wir erwachsen sind.
lo desenterraremos cuando seamos adultos.
para desenterrarlo 
cuando seamos mayores.
et récupérons-le 
quand nous serons grands !
e la dissotterreremo quando saremo adulti.
e desenterrá-la quando
 tivermos crescido.
и раскопаем, когда подрастём.