Feels a bit more than that but I haven't bothered to keep track. But I will say with my current pacing on maxing out the hearts, it won't be long before I do max out my 4 girls (not including Nuka who is already from start).

Hopefully they do throw out new girls on a normal basis. I haven't been able to find anything about this game so I don't know whats to come. I would assume its a original nutaku game or I'm just not googling hard enough.