In a sea village, there is a high school freshman, Da-young, who broke up with her boyfriend after summer vacation. Da-young, who has to write the most memorable thing for her vacation homework, writes down the lies of that summer day, recalling her memories with her ex-boyfriend, Byung-hoon.
Detective Ma Seok-do changes his affiliation from the Geumcheon Police Station to the Metropolitan Investigation Team, in order to eradicate Japanese gangsters who enter Korea to commit heinous crimes.
After being blinded in a coup against the king, Joseon's greatest swordsman goes into hiding, far removed from his city's anguish. But when traffickers kidnap his daughter, he has no choice but to unsheathe his sword once more.