Set in a fantasy world where humans and vampires coexist, the latter have evolved and no longer rely on human blood as food. Still, they are feared and discriminated against by society, causing many of them to hide their true nature and live as "normal" citizens, or else become outcasts.
Baek Ma Ri is a socially withdrawn teenage girl hiding her vampire identity. Driven away from several neighborhoods, she is eager to settle down in her new city and live quietly. But things change when she falls in love with Jung Jae Min, the most popular boy at her high school.
Set 3 years after the first season, members of the National Security Service (NSS) team, including Jung Yoo Gun (Jang Hyuk), Ji Soo Yeon (Lee Da Hae) and other agents attempt to pull the curtain on mysterious group IRIS.
Agent Yoo Gun is the leader of NSS TF-A team. While he goes up against Baek San (Kim Young Chul), Yoo Gun becomes involved in a case which changes his fate forever.
Cha Moo Hyuk was adopted by an Australian family but was abused and left homeless at an early age. One day he comes across Song Eun Chae, the coordinator for Choi Yune, a famous singer in Korea, whom she is secretly in love with. Her fateful encounter with Moo Hyuk ends up affecting not only her life but that of her precious Yune as well.
Because of an accident involving his ex-girlfriend, Moo Hyuk is left with 3 months to live. This leads him to head back to Korea in search of his biological mother. The discoveries he makes, changes his heart from longing to revenge. Even with all this darkness surrounding him, he finds an unexpected source of happiness with someone he did not expect to love.