no, his sister died but she wasn't the mother. their father just married his sister but already had his 2 sons
really I didnt know
where did you found/read it?
don‘t know.. it was mentioned somewhere in the manga
I see
I think it was around chapter 3. But to make it short, they're not related in any way except that his sister's married their father. They're his step-nephews. LOL.
now the drama is rolling in because the real mom is coming to get them back.
I thought the mom died?????