Kohryu: Beat arcade mode without continuing with ANY character
Uranus: Get to level 16 on survival then you should(not guarenteed) have her as an opponent beat her to unlock
Fang: Beat the game with everyone (includes Kohryu and Uranus)
The real way to unlock Uranus is to get to level 16 on survival mode and beat her. You can also start survival mode, select Random as a character, start the first fight then quit. Uranus and the Choas Labratory should be unlocked.
The way to do it as a glitch, technically you are supposed to beat arcade mode with one character not continuing, but if you select a character on arcade mode when the fight starts quit, then it should say, "You have Unlocked Kohryu", I have tried this 4 times and confirmed it.