Haha what? I kept skipping chapters but I'm sure that boy is still a kid.. Right???.. The artstyle is good but the plot is not- don't wanna be rude to those who liked it.. It's weirdly disgusting at some point. 2 stars for the art
They come from a family where they keep blood line by reproducing among them. Sister have children from parents or brothers but this time, Tsubaki, a gorgeous, cute male, is the last one. So there aren't going to be any more children. But, apparently, the blood is stronge and Tsubaru feels sexual attraction towards his older brothers.