It's been almost three years since Mei Tachibana and Yamato Kurosawa started dating. For their final summer vacation of high school, they make a return trip to the beach. But before they leave, Mei gets an unexpected message from Ren.
 
Meanwhile, Rin and Kai have also started dating...but after a secret from Kai's past is revealed, their relationship takes a turn for the worst. And finally, Megumi returns from Paris, but her trip abroad has changed a lot for her.
 
She's come back to Japan with a new look, but what other changes will she reveal from her sojourn in the city of love?