Anime identification request about guy with invisible pills (hentai)
As OP describe It sounds like The Invisible Stud contain nsfw image.

Synopsis:


  Mie happened to pick up medicine that an old man dropped. When he took the medicine, his figure disappeared. Soon he went to a public bath to peep, and began to molest. Then, he went to an all-girls school.


And there only three character Fujisawa , Mei and Suzu.