Weeks after no one acceptable has answered Rory's ads for a female roommate in Irvine, California, a professional woman from London offers to pay six months' rent upfront. The term is shorter than Rory had hoped for but better than nothing. And she seems friendly.

On moving day, Peter shows up with a letter from his sister. The agreement has to be canceled because of a sudden illness. For Rory, that means staying on the top ramen diet for a while longer while again searching for a roommate. But then she is caught between a rock and a hard place when Peter offers to continue the agreement since he needs a place to live while stepping up to replace his sister in the family business. Against the promise Rory made to have a female roommate only, she accepts the offer.

Rory was born out of wedlock and then orphaned, growing up with her strict and old-fashioned aunt. Peter was born with a silver spoon in his mouth and little or no responsibility. She is a naïve,...