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 this will be the last time 
the four of us swim together.
Also wird das das letzte Mal sein, 
dass wir vier zusammen schwimmen.
Así que esa será la última 
vez que nademos los 4 juntos.
Así que esta será la última vez 
que nademos los cuatro juntos.
Donc ce sera la dernière fois 
qu’on nage ensemble.
Quindi per noi quattro sarà 
l'ultima volta in cui nuoteremo insieme.
Então esta será a última vez em que
 nós quatro estaremos juntos.
Так что мы в последний раз
проплывём вместе.