For example Kati, one of the favorite characters.
Her design is simple but it is really sexy, those tight shorts and leggings, plus her kinda see through shirt is magnificent.
Since you trained with her, some chikan is good. There could also have been a grinding scene.
Anyways my point is, you don't need to put 3 bases on each character, every one oculd be different. Some may start eith base 2 already or almost base 3. That could make it more interesting.
Sorry if this seems like a rant, I honestly want to make a game like this after playing a lot of games from this genre and I want to help you since you already have a good foundation for a story.