There is a blank building next to the club headquaters. Can you turn that into a dojo/ training center.
My reasoning is simple. When engaging in areana combat you can use three girls. What about the rest? With the dojo you could in theory, place up to three girl in to train and gain a little exp not affp. Thus leveling up more girls at once. Clearly the one in your areana group would make more exp. But i think it could help players out ,espically newcomers.