This game features one or more gyaru heroines that have a tanned skin while not being ganguro. Kuro-Gyaru literally means Black Skin Gal (Kuro=Black, Gyaru=Gal).
This tag is used to differentiate tanned skin gyaru from ganguro so don't tag ganguro as kuro-gyaru.
Ganguro examples: link, link, link
With some exceptions a gallery of correclty identified Ganguros.
Kuro-Gyaru examples: link, link
Black Skin Gal