Sex, shopping, and sisterhood – for three young women in Manhattan, it's all about living life on top.

Sophie Steele, twenty-two and fresh out of business school, thinks she has it all: beauty, an MBA, and a high-powered job at a hedge fund in New York City. But Sophie's about to uncover a whole new life – a life filled with beautiful people, exclusive parties, and tantalizingly hot sex – when she moves into her older sister Bella's fabulous Tribeca penthouse apartment.

Bella Steele, a Penthouse Pet and Manhattan's hottest glamour model, can have her pick of rich, sexy guys eager to satisfy her every desire, and Sophie can't help but feel envious of her exciting, girl-about-town lifestyle. When her super-hot boss makes her an erotic offer she can't refuse, Sophie takes Bella's advice and starts to explore her wild side.

Meanwhile, Bella's about to start some experimenting of her own. She introduces Sophie and her best friend Maya Lin to Naked, the city's sexiest gym, where anything goes. It's there that Maya finds release through submission in an edgy, dark relationship with her boxing trainer, D, and all three girls let their passion take them over the top.