Human has evolved since 4 comets fall at the earth. New generation has an ability called trancenden, and the civilian with no ability called nonimmune. Haejin is a trancenden who could felt human emotion like his own, since meet up with Yoon, he intervened their life. Become special towards each other and become lovers. But earth didn't allowed it, Haejin is special case for trancenden, and they should apart for the humanity sake.
When the Star Sleeps