Tagusa and Yanna who visited the pool "Sun Beach Nikko River" called Waikiki Beach in Nagoya. There, he finds Yatogame, who is swayed by his cousin, Shiharu's selfish mama. For some reason, Shiharu hits off with Tsuchiba who came to play by chance ... There are seven sails and teachers in the pool, so it's a peaceful atmosphere! But does anyone forget?