Based on the erotic game by Noesis.

Yui Kurahashi quarreled with her parents and ran away from home. As Yui walks around town, Yui meets a friend and Yui has been fooled into joining a dating site called Free Friends. Yui's just waiting for someone to contact her even though Yui does not know much about it. The main characters accidentally find it and its contacts. That night, they met in a city full of libido and....

(Source: Translated and Edited from Nekopoi)