Jiho learns how he was born half human and half animal and finds out there is going to be a special gift that he will recieve on his 20th birthday. This gift- a marble- is the only way to become a real human. Despite the perfect plan he had, the "marble" gets taken away by Gunwoo, accidently, and Jiho has to convince Gunwoo to sleep with him so he can become a human before it’s too late. Jiho slowly falls in love with Gunwoo as he tries to get closer to Gunwoo.