Super Gals!

The series revolves around the kogal (also known as "gal") subculture in Japan. The title character, Kotobuki Ran (Ran Kotobuki in the English anime: CMX maintains the Japanese standard of family name first, while ADV follows the Western order), is the self-proclaimed "world's greatest gal." As a teenager in Shibuya, she's determined to live out the gal lifestyle for the rest of her life, and she has gained a reputation as the most respected gal in all of Shibuya. However, she comes from a family of police officers—her grandparents, her parents, and her older brother are all officers, and her younger sister is set on following in their footsteps. Ran has other dreams for her future, but as frequently shown, she has acquired the family's sense of justice and spirit.
Gals! doesn't always showcase Ran's point of view. It really consists of teenagers who live the same life as regular students and kogals in Japan. There's romance, troubles, drama and insecurities, especially Miyu and Aya's (since they take their relationships much more seriously than Ran).
As a result of its reference to this lifestyle, ADV has given the series a 15+ rating, since many Americans unfamiliar with Japanese culture might see the lifestyle, especially the part of it pertaining to "enjo kōsai" as nothing more than prostitution, which is illegal in Japan.

Wikipedia