its about a girl whose big brother died because of accident and then the big brother soul went into her body. the sweet big bro help her and encourage her all the time.
Quite moving story about moving on after a truly remarkable and loved person has passed away. It's one of those stories that manage to move you even though you are already aware of the end.
So fluffy and cute, that one tends to forget the dark reason for the story - the complex storyline keeps one on the edge for fear of Masago breaking down without further warning