Responses
They're not blood-related. When his sister married Ren and Takumi's father, he already had the twin. http://www.mangago.me/read-manga/futari_no_musuko_ni_nerawarete_imasu/mh/c001/13/
Because the man he's sister married already had twins with another woman so teh twins were her step sons and Takumi adopted them and so therefore they weren't blood related
Ooh is that so thanks!
So hot, so good, so beautiful! Love the art and the plot! Hoping for more showing more the jealous side of the twins, btw i'm just confused, if takumi and Ren anre the son of his sister why they always emphasize that they are not blood related?