Not bad at all. You put effort into it, and it shows. It was cute. The characters might be just a little bit OOC, but not too badly (InuYasha struck me as just a tad off, but it's hard to get him right without falling into lots of angst or fighting), and you might not want to use the Japanese words in an English fic. They're disorienting, and not everyone knows what they mean. But you definitely have potential. ^^
Author's response
There is a sense of out of character but... if you pay close attention when reading the manga or watching the anime, you can see the tender side of him towards her, so it isnt tooooo far off. thanks so much Positive feedback is glorious haha.
Plus, I enjoy putting in the slight mix of words because it brings the readers to the attention that this isn't being spoken in english without actually having to write the ENTIRE thing in japanese. ^_^ plus its a fun little thing to pick up