Tetsuro, who runs an IT company in Tokyo, returns to his hometown of Esashi, Hokkaido, to attend his grandfather's memorial service. Having discovered his business partner's betrayal, Tetsuro goes out for drinks with Yuki, a classmate he hasn't seen in 20 years, and they reminisce about their youth. There, Tetsuro, who was on the sailing club, comes up with the audacious challenge of circumnavigating Hokkaido without stopping at any ports.