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.
Things aren't the way they used to be.
Die Dinge sind nicht mehr so wie früher.
Ni las cosas serán como 
cuando estábamos en primaria.
Las cosas no son como cuando 
éramos mocosos de primaria.
Les choses ne sont plus 
comme en primaire.
Non possiamo rimanere fermi 
ai tempi delle elementari.
As coisas não são mais 
como costumavam ser.
И всё уже не так, как раньше.