“Dolphin blade” is a marine race sport featuring girls in swimsuits on motorized float shoes. It is especially popular in Yamato, the 81st island district of the United Federation. Kousuke is an employee at the leading Aihara Electronics Corporation. His business performance was excellent thanks to sweet-talking his boss and he appeared to be on the track to certain success. However, his boss was then dismissed for an ‘indecent act’ and he also came under suspicion of similar conduct. Despite being spared a similar fate due to lack of evidence, he was involuntarily transferred to a sub-subsidiary as the new manager of a dolphin blade team. Even though the team had some skilled members, they were unable to attain any good results every year, accruing a huge debt in the process. He would not be able to return to Aihara if the debt is not fully paid off. It was clear that the upper management intended to get rid of him, but he was determined to do his best to prove them wrong.