Sugarhoneyicedtea's Manga

This really needs an incest tag. They're twins, so if you're not into that, don't read it

For those worrying about the depiction of child sex slavery, it doesn't show it at all. It does however show the mc raping the ml in the first chapter. Other than the rape and mc saying he was sold into sex slavery for a month before being abandoned, its safe to read.