Jun Hagimori

Takagi loves playing good-natured pranks on her classmate Nishikata. But try as he might, he can never prank her back — she's just too clever!

Takagi, now grown up, revisits her middle school as a trainer. She encounters Nishikata, her former classmate she used to tease, now a PE teacher there. Their playful dynamic resumes, leading to more interactions between the two.

Nagasaki in 1986. Young friends Hisada and Takemoto decide to go to Boomerang Island to "see the dolphins". The friendship between the two deepens as a result of this adventure.