Originally Posted by Orange00

Anyone know how to unlock most of the girls? There are like 5 girls that you need serial codes to unlock them, can I get some help on unlocking them?

The codes are not to "unlock" girls - they are not locked to begin with (unless you have them and protect them from accidental discharge that way, but that's entirely another matter) You can roll them from normal gacha if you are lucky (or from premium, if you are unlucky XD)

These codes will simply grant you their content girls outright.