I'll try not to reveal too much, but the character endings are closely tied to the story endings. The story and gameplay changes drastically with each character route.
I didn't like, that they are only fighting on the internet, as you are told in the very start of the game. The story is, however, so good. You should definitely give this game a try and stick with it for a bit (lots of romance and drama, if you are into that too). I sort of hate VN's as mediums. I played for the fighting and the mechs, but I stayed for the story, as it really got to me.