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.
Why didn't you tell us?
Warum hast du uns das nicht gesagt?
¿Por qué no nos dijiste?
¿Por qué no nos habías dicho nada?
Pourquoi tu n’as rien dit ?
Perché non ce l'hai detto?
Por que não nos
 contou nada?
Почему ты не рассказал нам?