While on the way to work, Yuji Shin sees a swallow lying weakly on the road. I hate bothersome things, but I can't ignore the injured swallow. I heal the wounds and take care of the swallow. However, the reality is that I am a college student who is already tight on money to take care of myself, so I will soon return the swallow... “Don’t forget the gourd seed when you come again…" The swallow, who just flew to the mountain spirit, asks for the seed so that he can repay his grace, but the time is already in the 21st century. The gourd seed, which will repay his favor, doesn't exist anymore. "Then what should I do...?" “Who care about the gourd seed, just repay the favor with your body!!” Will the swallow be able to safely return the grace to Yuji? A project to repay the full-fledged grace of the Swallows who came to fill them with their bodies because the gourd seed wasn't there! (Gourd seed and Mr. Park share the same letters in Korean)