Imouto Reshipi <e-moterecipe>

A young genius doctor gets into a traffic incident while on a date with his beloved sister. When he wakes up at a hospital he is shocked to know that was the only child and never had a sister. He does not believe them since his perfect sister must exist in this world. He is not genius for nothing! With the help of forbidden practices, Tibetan secret arts and climax love juices from two girls he's going to recreate his sister!

[From vndbreview]