Meeting up again

After graduating college and pursuing different careers the swim clubs mostly loose contact, only having each other's phone numbers buried in the bottom of their contacts. But Makoto, Rin, and Haruka decided to meet up. And do what exactly? Travel Europe. The trio has three weeks to enjoy each other's company in Europe. Although don't seem to realize...
These three weeks might be the last they see each other,
For a long long time.