I just started this and I can't tell if the flashbacks are to his relationship with Si On in the Lawyer world…
I kind of feel both is possible. Perhaps both versions of him were living the same life before a certain turning point. And the flashbacks may have been part of their shared history. I think even the parallel world version of himself wasn't always a good guy, but he redeemed himself very early on
But srsly, what's this drama gonna be about?