Originally Posted by fndkgnz

I believe so, they're girls that have codes that are obtained from Japanese novels. They are much harder to obtain outside of Japan, depending on where you live. However, I'm not sure if it's even possible to use the codes on the Nutaku version.

The only code available now is for Violet Tulip, but I don't know from where you get it.
Before that, the code page was closed...