[Akito Kinomoto]

Nudity (except the non-explicit kind) could make a show adult but not mature. And I say could because I wager some ecchi series are made for the teenagers who just discovered hormones. At any rate I wouldn't take one culture's higher or lower tolerance for certain content as a testament to its maturity or lack thereof since it's all relative; what's a big deal in one culture could be casual in another and vice-verse.