Nahhh he's adopted. His biological mother is the friend of his mother/ stepmother right now.
In the novel he is their biological brother but they changed it for the webtoon bcs it's illegal to depict incest in webtoons in korea, they basically went around it by depicting it as psychological incest
THERES A NOVEL? PLS DO TELL
There is but personally I buy the novel on ridi so Idk if there's a translation out there :<
Is ilodel really there brother or not