Following because I am dying to know too.
Just a very sketchy spoiler. I can't tell you in detailed way bcs I forget some parts to somehow xD
The seme and the uke were close when they were in middle school. The seme was rumored as gay and that he slept with his hyung (the blonde guy). What I get is the seme and the blonde guy weren't really related, but the seme lived with him somehow. And the blonde guy wasvery possesive with the seme. One day the uke seduced the seme then they were fooling around (and the blonde knew through CCTV). Shortly, there were some angsty moments like the family of the uke passed away, some accident with the seme caused by the blonde, and then the uke were traumatized until he lost his memory, and I guess there was misunderstanding. Something like that.
*some parts too
Does anyone feel like sending spoilers of what happened in their past? Plsty