Akaten Doushi (“Comrades In Failure”) [English], by Satou Shouji

Akaten Doushi posed me difficulties I didn’t expect, I kept on writing “Akaten Doujin” and calling the artist “Sato Shoujin” ^^;

Apart from that, this is a simple story, about a highschool teacher giving private class help to a cutie, and gradually winning her heart. He’s totally oblivious to the alchemy going on until he finds her unzipping his pants.
After this, the whiteout censorship is a murder, but at least, we get to see nice vaginal sex (the censorship apparently being mostly focused on the male genitalia, go figure why.)