In a dystopian 2071 devastated by air pollution, the survival of humanity depends on the Black Knights — and they’re far from your average delivery men.

A talented martial artist who can’t walk past a person in need unites with a probation officer to fight and prevent crime as a martial arts officer.

Ean has a critical missionto return to the future to save everyone. However, she becomes trapped in the distant past while trying to prevent the escape of alien prisoners who are locked upin the bodies of humans. Meanwhile, Muruk, who helps Ean escape various predicaments, is unnerved when he begins sensing the presence of a strange being in his body. Traveling through the centuries, they are trying to prevent the explosion of the haava.

Romance is sweet and bitter — and life riddled with ups and downs — in multiple stories about people who live and work on bustling Jeju island.