I think it was a fine enough ending. It started to make me anxious already when it looked like Kouta fails time after time at telling Natsuki how he feels. But of course it had to be that kind of a last minute dash. Natsuki might have been a bit more romantic but then again she always kept her feet firmly on the ground, even if it made it look like it's all the same for her and she lets Kouta alone decide whether anything is ever going to happen between them. But I suppose that was her responsibility as the older one. She couldn't very well pressure the kid.