Sugar Bottom "Present"
 After being struck by a car, a girl named Sarah Speed loses her dream of running in the olympics. That is until a young but old demon offered to fix her legs at the price of her virginity. Not much use for a demon but for a human, such a thing held great emotional ties, at least for Sara. After much thought she eventually agreed but only if the demon helps her start a sports club at her preppy all girls school. A place where disgustingly "PROPER" young ladies are... manufactured. 

 You can find this Manga on Tapastic, Webtoons