Fifteen-year-old Derek (Michael Seater) is unhappy about his dad's remarriage, mostly because it means he now has to deal with two stepsisters, the older of whom has her heart set on taking over Derek's bedroom. Casey: Ashley Leggat. Edwin: Daniel Magder. Lizzie: Jordan Todosey.

Casey meets resistance from her siblings and parents when she tries to create order amid the chaos that is their home life. Meanwhile, George needs help from the kids if he's going to pull off an important book club meeting that's taking place at their house while Nora is away on a retreat. Mr. Davis: James Codrington. Linda Davis: Catherine Burdon. Amy: Kayla Mills.

A budding romance between Casey and Sam seems to have little chance of growing after Derek informs Sam of the “male code,” which prevents friends from dating their best friend's siblings. Elsewhere, Nora and George take a quiz to determine how well they know their kids.

Casey gets more than she bargained for when she attempts to add a feminine touch to the living room and, in the process, starts a decorating feud between her parents. Derek: Michael Seater. Edwin: Daniel Magder. Nora: Joy Tonner. George: John Ralston. Casey: Ashley Leggat.

Casey is enraged to learn that she has been labeled a “grade grubber” by her fellow classmates. To rid herself of this unflattering rep, she decides to team up on a school project with the biggest slacker she knows: Derek. Michael Seater. Marti: Ariel Waller. George: John Ralston. Nora: Joy Tonner.

As Aunt Fiona's wedding planner, Casey strives to make the ceremony and reception absolutely perfect and hitch-free, but things start to go wrong when Casey's cousin---and archrival---Vicky (Sarah Gadon) interferes. Meanwhile, Derek gets his first directing job: He's been asked to film the nuptial celebration. Fiona: Tara Manuel Rigal. Nora: Joy Tonner.

Derek makes Casey an offer she can't refuse. She agrees to run his highly profitable school-based business in exchange for a new cell phone and a more desirable locker location while he's at home recovering from chicken pox.

Casey engages in a high-stakes game of chance against the master of cheating siblings, Derek; and George finds himself in hot water for mentioning his ex's name during a heated argument with Nora.

A budding romance between Casey and Sam seems to have little chance of growing after Derek informs Sam of the “male code,” which prevents friends from dating their best friend's siblings. Elsewhere, Nora and George take a quiz to determine how well they know their kids.

Casey wonders whether Derek has an ulterior motive when he asks her best friend Emily (Shadia Simmons) out on a date.

Derek is forced to spend time with Lizzie, teaching her hockey; Casey offers Edwin romance tips.

Casey decides to get rid of her goody-goody image in an attempt to get Trevor to go out with her---and win a bet with Derek.

A popular girl named Kendra (Lauren Collins) has an ulterior motive---involving Derek---when she chooses Casey as her partner for an English project.

Casey goes against her mother's wishes when she invites her birth father to the house for dinner on what turns out to be an evening filled with surprises---most of them bad.

Kendra (Lauren Collins) sets Casey up on a date, which doesn't go well; Derek plans a party, with unsolicited help from George and Nora.

When Derek already has a girlfriend, Casey is shocked when he asks out a friend of hers, Lucy. Casey asks Emily to dig up information on whether Max is available or not. Meanwhile, Nora has set up a dinner with another family, but some members of her family object.

Derek defends Edwin from a bully.

Casey tries to make a movie for a school project.

Derek lands a leading role in a school musical, and Casey gives him acting advice.

Derek swaps test papers with Casey and then devises a plan to keep from getting caught.

Derek's mom tries to get him to live with her in Spain for six months.

Derek breaks up with Kendra to get out of buying her a Valentine's Day gift, so she asks Max to the school dance.

Max gives Casey his football jacket, which apparently causes her to develop allergies.

Derek gives Edwin dating tips, but they don't seem to work for him.

Derek refuses to help out with Marti's birthday party despite being asked by Sally. Casey wants to get back together with Max, but he is hesitant about the whole idea.

After Derek has trouble expressing his feelings for Sally, she recommends that he write a love song for her. Meanwhile, Edwin tries out his talent show comedy routine on George and Lizzie.

Even though Sally had one friendly dinner with her ex-boyfriend, an irritated Derek decides to spend time with Kendra to make a point that girls and guys can't be just friends. Casey attempts to counter Derek's argument by searching for a male student that she can be friends with. Meanwhile, Edwin fears that George's female co-worker who is coming over for dinner is out to steal his father away from Nora.

While the rest of the family heads off to Quebec for spring break, Casey and Derek decide to stay home to meet their previously planned engagements. However, the two discover that they now have to spend the entire vacation together when their original plans don't work out.

Casey is hurt by the six and a half out of 10 that she receives from a new guy at school who starts ratings girls, and whose ratings Kendra plans to use in selecting models for an upcoming fashion show.

Derek breaks up with Sally after she reveals her plans to attend a university in another province. Believing that he is hurt over what happened and is bottling up his feelings, a concerned Edwin and Casey try to get him to open up. Meanwhile, Lizzie and Marti attempt to keep a dog hidden from most of the family.

Derek plans to drop of out of school to be with Sally in Vancouver.

Casey is in panic mode after the diary that details her unsettling romantic dreams about Truman goes missing. Believing that Derek and Edwin took it, Lizzie and Marti attempt to get the diary back by making their stepbrothers' lives miserable.

Casey spends the day with George at his law office where her need to organize things doesn't mesh well with the way he usually does things. Meanwhile, Derek tries to help Nora land a business deal with a client.

Casey gets stuck with Truman as her fencing partner in gym. Meanwhile, what starts out as a friendly game of table-tennis between Derek and Edwin turns into an ongoing competition to figure out who is the best player.

As George prepares a Mexican fiesta for their second wedding anniversary, Nora gets a reluctant Casey to tell the story of how she and Derek first met.

While his parents are away for the weekend, Ralph stays at Derek's home where he begins to develop a crush on Casey.

After entering a tv dance contest, Casey must find a new dance partner when the previous one pairs up with her rival. Meanwhile, Lizzie dares George and Edwin to eat only healthy food for a week.

A surprise visit from Edwin's friend Teddy turns into a frequent occurrence that makes the entire McDonald-Venturi household uncomfortable. Despite warnings from Emily, Casey decides to go out on a date with Truman.

To be eligible for college athletic scholarships, a "D" average Derek seeks George and Edwin's help in passing all of his final exams. Meanwhile, Nora and the girls try to get a stressed out Casey to stop over-studying and relax.

Derek serves as a chaperone for Casey who is going to a party in Toronto with Truman. Meanwhile, Lizzie goes out on a date with a boy that the family has never met.

As the prom approaches, Casey and Derek both find themselves without a date. Meanwhile, George and Nora have something to tell the family.

A worrisome Casey is having difficulty writing her valedictorian speech for graduation. Meanwhile, Edwin is concerned that he won't be able to live up to Derek's reputation at J.S. Thompson High when he goes there in the fall.