ok so from what I remember, basically:
when they were little, chaejun would play around a construction site that seung-hyeon would pass after taekwondo. they would talk and play together, and one day they played hide and seek (I remember from one of those earlier flashbacks), and I'm guessing that was how chaejun got locked in the warehouse, because chaejun was the seeker and seung-hyeon told him to count while he hid. so far we don't know how chaejun got locked inside, but his uncle was the one who saved him (and got that giant scar on his arm), and i'm guessing chaejun got his forehead scar from that incident as well.
when they were little, chaejun would play around a construction site that seung-hyeon would pass after taekwondo. they would talk and play together, and one day they played hide and seek (I remember from one of those earlier flashbacks), and I'm guessing that was how chaejun got locked in the warehouse, because chaejun was the seeker and seung-hyeon told him to count while he hid. so far we don't know how chaejun got locked inside, but his uncle was the one who saved him (and got that giant scar on his arm), and i'm guessing chaejun got his forehead scar from that incident as well.
AAAAAAAAAAAAAAAAAAAA