Help

Do you guys know a shoujo manga about a girl who has a crush on her sisters boyfriend. Then one accident cause the guy to be blind which caused the sister to leave him. But the girl didn't and still took care of him. There was a scene where she made a hundred? paper cranes to him. Then when the guy got his sight back the sister came back so they can have a wedding but it didn't continue since the guy knows she isn't the one who took care of him.
Pls help me