Hera planet, 4443 A. D. After a long time of enduring resentment and cold attitude from his partner, later experiencing bankruptcy, Cheng Jin finally decides to let him go. However, as if it's destiny, his lover suddenly lost his memories and fell in love with Cheng Jin. Cheng Jin was overjoyed, but at the same time anguished as he anxiously awaits for this love's “limited time” to arrive.

Initially, Li Li only wanted to sleep with his roommate once, so he could get some money to help his family. But he didn't expect that before the crime' could be committed, he would be caught red-handed by his roommate's older brother, Yan Wen, who got evidence and warned him to stay away from his younger brother. Li Li thought Yan Wen hated him, but when he had no one else to rely on, it was Yan Wen who offered a helping hand. A contract of support then changed the two's relationship forever