I think she did it on purpose... just to play with them she doesn't want them to feel alone..lonely,,just like what she did when hikari left then seiji was sad..
In a sense you're right. Though she thought it Seiji, the guy she was being a good girl for all those years, the one thing she remembered the most about him being that promise, was Hikari. So wasn't she really waiting for Hikari all that time and in love with him? And isn't he the one who even as a kid wanted to return thought to make her that promise? Looking at it that way Seiji stole Hikari's long awaited girl from him.
Same he should have ended up with her
I wanted Hikari to be the one.
He was the one that made the promise.
That girl is so dumb, why cant she tell the difference between the 2 boys! >:/