Based on the CG collections by Miyahizuru (みやひづる) and Nemunoya (ねむのや).

When a school girl takes shelter from the rain at a bus stop, a middle-aged man comes...
After some time of chatting the man suddenly assaults and r*pes her over and over again.

(Source: DLsite English)

Note: A live-action AV adaptation (MIMK-046) was released on October 1st, 2016.