Jeon Wonwoo, one of the 13 professional officers known, found himself in a very unexpected situation. While they were all looking for clues for the mysterious case they were tyring to crack, Wonwoo happened to find another him from a another timeline solving the exact case.

These 13 boys who had normal lives just like any other except for one special thing. They had each other. Travelling together, sleepover at someone's house, pulling each others legs and above all standing up for each other against anything even if their own parents were something that happened along the years. one day whatever they considered as normal lives made an unexpected change during one of their hang outs that impacted them individually.