Fiona, Marcus' mother, is a Granola Girl who doesn't initially appreciate living next to the red meat-loving Will or the fact that her son is spending so much time with a grown man. But she comes to appreciate (often grudgingly) that Will provides a masculine influence to Marcus that she can't provide.
Also featured are Andy and Laurie. Andy is Will's best friend and is constantly trying to get Will to grow up and settle down while occasionally yearning for the freedom he had in his youth. Laurie is Andy's wife and she and Will tolerate each other, at best, for Andy's sake.
The pilot incorporated elements from both the book and the film adaptation before the rest of the series moved onto original storylines.
This series provides examples of:
- Adaptation Expansion: The series compresses plot elements from the book and movie into a single half-hour episode. The rest of the show explores original story lines based on the sources' concepts and expands the cast in order to do so.
- All Girls Want Bad Boys: Gender inverted; Marcus, who couldn't be more of good boy if he tried, falls head over heels for Shea Garcia-Miller when she sneaks into the principal's office and blares the Sex Pistols on the PA system.
- Aww, Look! They Really Do Love Each Other: With their very conflicting lifestyles and values, Will and Fiona's relationship is bumpy at best. However, they will put their differences aside and help each other when needed, usually for Marcus' sake.
- Casting Gag: Chris Diamantopolis guest stars as Marcus' new teacher and his introductory episode includes Will being psyched for a The Three Stooges marathon on TV.
- Disappeared Dad: Marcus' father is a penguin researcher who would rather spend months isolated at Antarctic research bases than spend time with his son.
- Granola Girl: Fiona is a textbook example. She is a vegan, believes in homeopathic medicine, makes nearly everything she needs at home, conducts rebirthing rituals with Marcus, and that's just the tip of the iceberg.
- Marcus is a male version, thanks to his mother's influence, but Will's influence is starting to rub off on the boy, namely in how Marcus now loves meat, especially barbecue ribs.
- Hidden Depths: Will, as it turns out, is a classically trained musician but he rarely talks about it because he associates it with his distant father.
- Ladykiller in Love: Will finally finds himself in a happy long-term relationship with Dr. Samantha and even moves to New York with her in the first season finale. Unfortunately, in Season 2, Dr. Sam realizes that Will misses living in San Francisco and being near Marcus so she breaks things off.
- My Beloved Smother: When Fiona says Marcus is her whole world, she really means it. Her list of over-mothering acts includes picking all his clothes, spending hours of new-age rituals together, and trying to negotiate friends for Marcus with other mothers. The one time she lets Marcus be home alone for a couple of hours, and he accidentally stabs his foot trying to peal an orange, she goes into overdrive, placing two-way cameras around the house.
- Papa Wolf: Will becomes very protective of Marcus and seeing Marcus get pushed around or be upset is one of the few things that gets Will riled up.
- Parental Substitute: Although their relationship started out as a business arrangement, Marcus quickly took to Will and looks up to him. Will took a while longer to come around, but came to realize that Marcus is lacking a male role model and steps up. They maintain regular contact during the gap between Seasons 1 and 2 when Will was in New York and Will makes sure to set aside time to spend exclusively with Marcus when he visits San Francisco in the Season 2 premiere.
- Parent with New Paramour: When Fiona starts a relationship with Mr. Chris, Marcus is so unhappy that he tries to run away from home. What's really ironic is that Chris was Marcus' favourite teacher until his mother broke the truth to him.
- Parental Neglect: Shea, the local bad girl, is regularly left alone at home by her mother, and she hasn't seen her father in six years.
- Pitbull Dates Puppy: Will's best friend, friendly and mild-mannered Andy, and his wife, aggressive and domineering Laurie.
- Promoted to Opening Titles: Annie Mumolo, who recurred in Season 1 as Laurie, Andy's wife, became a series regular in Season 2.
- Rich Idiot with No Day Job: Will wrote a Christmas song many years before that became a hit and provides him with fat royalty checks every month. He is determined to live out the rest of his life doing whatever he wants. This lifestyle is threatened in Season 2 when someone claims to have been a co-writer on the song and the royalty payments are frozen until the issue can be sorted out.
- Stalker Without a Crush: Marcus has very little regard for Will's privacy, going through his phone history on a whim.
- Unwitting Instigator of Doom: During the time Will moved to New York with Dr. Sam, Fiona ran into his old Stalker with a Crush Stacey, and inspired her to value herself more and not settle for less. Stacey took this to mean she should sue Will for his song royalties.