The Republic of Korea, where humans and beastmen, beings of opposite poles, coexist. 'Tae-seong', a shark, has to win the prize money in a swimming competition to pay off his loan debt, but his rival 'Yun-jae' loses the first prize each time. Then one day, Tae-seong finds out that Yoon-jae is actually a 'human' in the shower room, and tries to threaten him to pay back his debt on the condition that he keep the secret, but somehow it doesn't work... “If you want to pay off your debt like that, come and suck my bottom when I call, fuck you