The rainy season came and went, leaving behind both strengthened friendships and jumbled feelings alike. Natsuki Haibara started his journey seven years back in time with his heart set on the school's cutest girl, Hikari. However, after Uta's persistent advances and a daring Tanabata festival date, he's forced to accept that his heart is wavering.

Summer break is fast approaching, and what screams youth more than the blue ocean waves? Natsuki and friends plan an overnight beach trip together, but things aren't easy when super strict parents come into play. As he learns about Hikari's hidden past, Natsuki realizes there's more to her than the bright school idol she seems to be. Will he succeed in making this the best summer ever for everyone? Or is there a line between friends and family that just can't be crossed?