Not 120~, but ~120.
You supposedly get some from Portal of Chaos however it works and recycling girls is easy to do as you get a fair amount from factory and clearing stages.
The only problem about blueprint is waiting til a girl you want appears.
The fact that the game even has this feature is rather generous. Other games would never have features like this in-game and even then, other games require you to get several copies of the girl to even max her to full potential.