Futago Mono Twin Pack

Minoru has had better days. Both his parents are dead and he’s been living by himself for some time now. Things soon change as he comes across a video that shows his mother holding him and another child! Soon thereafter, two girls show up claiming to be his twin sister and younger sister respectively. They all decide to live together. Then somehow the teacher and a couple of his female classmates become potential prospects. Now there are two versions of the same plot; Pure and Dark. Pure follows the pure love route while the Dark version goes into S&M and bondage.

[From White Masq]