Guys I need help finding an anime. I don't remember much except >> there is this gir...

Guys I need help finding an anime. I don't remember much except >> there is this girl who gets into an accident (bus collision) and goes in coma and the guy who (I think) likes her creats this another girl (white haired) and sends her into the past to prevent that accident...but the past him ends up falling in love with her or something like that .......I honestly can't remember please help me out -^- -^-