Aspiring writer Hong Nan-hee is a foul-mouthed, disheveled and jaded single woman struggling with life and love. She and Byun Hyung-tae have been best friends for most of their lives. They cook for each other, call each other daily, bicker like siblings, and support each other when things go wrong. But everything is about to change. On her 30th birthday, Nan-hee realizes that she needs to shake things up. She begins dating Kim Jung-joo, a talented baseball pitcher
who is aiming to play in the American big leagues; but Nan-hee's mother disapproves of their relationship because he is eight years younger. Tired of living with her mother, she rents Hyung-tae's house while he is on vacation, but complications arise and soon the two friends are living in the house together. As the old friends navigate new territory, they start to discover things they never knew about each other — he's neurotic, she snores — but more importantly, they gradually realize what their friends and family have always suspected — that, without realizing it, they've been the most important people to each other all along.
