Woo-jin is Korea's top star - every item he wears and uses are always a hot potato and gets sold out overnight. He is especially famous for remembering all his fan names. He seems to be just perfect, but there is one big secret that nobody knows - he cannot forget but only remember things. Woo-jin is forced to relive painful moments over and over again, feeling the same amount of anguish each time. One day, Woo-jin encounters a woman named Hae-soo, who suffers from the opposite pain from him: her memory resets every 30 days.

An eager but naive intern begins working at a prestigious ad agency, only to fall for his handsome, hard-nosed boss.

Two elementary boys, who are best friends and baseball fanatics, had to be separated as one left Korea to pursue education abroad. Many years later after returning to Korea for high school, the boy had found his best friend to have only turned into a girl instead.