We follow perpetually-single Will as he attempts to woo women, while avoiding any real commitment. His life changes when a quirky, bohemian, vegan single mother, Fiona, and her 11-year-old son, Marcus, move in next door. Marcus is a misfit, and already being bullied at his new school, yet he and Will strike up an odd-couple friendship, under Fiona’s disapproving watch.

Will agrees to babysit Marcus so Fiona can go on a job interview, but a last-minute invitation to a party complicates the situation.

Will struggles to pull off a guys' night out. Later, Andy asks Will to be his son's godfather.

Marcus asks Will for advice on how to get invited to a girl's birthday party.

Fiona gets dating advice from Dakota.

Will takes Marcus to the ER after an accident with a knife.

Fiona intrudes on Will's poker night. Meanwhile, Marcus goes on his first sleepover.

Fiona oversees a project for Marcus' class. Later, Marcus goes on a shopping spree with Will.

Will invites Sam to a game night hosted by Andy and Laurie.

Scheduling problems arise as Will tries to plan a birthday party for Marcus. Meanwhile, Fiona and Sam get into a disagreement.

Will invites Sam to move in with him after she is forced to evacuate her apartment. Later, Will and Marcus build a tree house.

Will turns to Andy for advice after Sam gets a job offer in New York in the Season 1 finale.