When her father accepts a promotion overseas in Japan , high-spirited 16-year-old Holly has no plans to head to Japan with him. She decides she'd rather live in the New York City with her "straight-laced" sister, Valerie. In the opener, Holly's attempts to prove herself a perfect roommate backfire when she misinterprets a remark about Feng Shui and rearranges the apartment. To make matters worse, Holly jeopardizes Val's job with a marketing firm when she disrupts a promotional event featuring skateboarder Tony Hawk.

Holly and Val plan a day of at the spa, but Holly finds herself in a 'muddy' situation when she sneaks out of the spa without Val's knowledge in order to meet J.C. Chasez from *NSYNC. Holly must somehow get back inside after being denied re-entry by a security guard. Being Holly, you know she always finds a sneaky way to do things, so she climbs in through a window landing in a mud bath with a naked lady! Meanwhile, Jeff and Gary have an afternoon of male competition after Gary calls Jeff old.

When Holly's unintentionally disruptive antics finally become unbearable, Val creates a G.R.C.--a Good Roommate Chart--for Holly to follow. Afraid of being sent to live with her father in Japan, Holly strictly adheres to the obsessive regulations, but a mishap involving Gary and dozens of Val's stuffed animals might just mean the end of this living arrangement. Meanwhile, Val and Jeff think they've found the perfect opportunity for some much-needed romance--but Holly's violation of the G.R.C. ruins that plan.

Holly and Val battle for possession of a teddy bear they both cherished when they were younger. When the struggle becomes too divisive, the sisters agree to give the stuffed animal to a little girl in their building. However, upon discovering that the child is abusing and destroying their childhood treasure, Holly and Val join forces to regain the beloved bear.

Val tries to be less of an authority figure to Holly, but Val's patience is tested when Holly and Gary secretly leave for a wild party on Long Island. Worried, Val and Jeff snoop in Holly's e-mail and go after her.

Holly becomes smitten with a young man, Kyle, who is leading a protest movement to allow the zoo's performing parrot to retire, but things fly out of control when Kyle is so inspired by Holly's passion for the cause that he kidnaps the parrot. Meanwhile, Val plays matchmaker for a customer who reveals she has a crush on someone in the restaurant, until it is revealed that the object of her affection is Jeff.