OVA Furachi (Outrageous) 2 (Region 2)

Here's the hentai OVA adaptation of Urasuji Samurai's popular h-doujinshi, Furachi (Outrageous), produced by Lune Pictures.

When security worker Kai gives his old pair of binoculars one last hurrah, he doesn't look up at the night sky... but across the street, into the charming Ikenaga's window! When he runs into her one day outside his apartment, she doesn't seem to realize he's been eye-fucking her every night. In fact, she asks him on a date! Ikenaga tells him everything she's from a small town and moved to the big city for the thrill, which is why she's been masturbating in front of an open window every night with a clear view into the apartment across the street. She knows exactly who Kai is... and he can forget the binoculars, because she's ready to go at it with him all night long.