Characterization was good overall, but Sakura's reaction was a bit flat, and the way Tomoyo finally spilled the beans felt off somehow. I'm also a bit confuzed that Kero sort of... disappeared at the end.
Writing wasn't stellar, but not really BAD either. If anything, it was vacant, especially nearer the end. There was a touch of character insight in the beginning, but after that everyone seems to just be going through the motions. There were a couple of places where the discription felt awkward too.
Overall, not a bad peice of writing, but a distance from noteworthy. Keep working, though, and I think you'll turn out some really good stuff