To be accepted to the cheerleading squad Ashley must perform a mean prank on Mary-Kate's new friend, Gabrielle. Ashley soon learns that nothing is worth doing something so mean to another person; Carrie convinces Kevin to take a day off work and the two go to a ballgame together.
Carrie has plans to go to South America for the summer. The twins trick Kevin and Carrie into having dinner together at a restaurant. At the airport, Kevin is disappointed to see Carrie is traveling to South America with a classmate. Carrie kisses Kevin, and boards the plane.
The twins are paired up with male partners for a school assignment to teach them about marriage; Against Kevin's wishes, Carrie goes on a date with Matt.
Kevin is not pleased when his brother, Matt, comes to visit. Kevin knows his brother is immature and unreliable, which becomes increasingly clear after an incident at a hockey game.
Mary-Kate and Ashley places a bet with the school's fund raiser money; Carrie becomes jealous when Kevin starts dating one of her friends.
Trouble starts when Carrie moves into Kevin's basement.
Mary-Kate is forced to teach Ashley all about sports when she develops a crush on Eric, a sports fan; Kevin must appoligize to Carrie when he causes waves in their friendship.
Carrie's old boyfriend, Alex Reardon, is back in town and Carrie feels she must make herself look as successful as he is. Carrie convinces Kevin to pretend to be Carrie's fiance to make Alex jealous; The twins have a party which doesn't go quite as planned.
Carrie accepts Kevin's invitation to send Christmas with him and the girls. Carrie brings a homeless man, Walter, as her guest to Christmas dinner. Sometime during dinner, everyone is shocked to find Walter stole all the gifts.
Ashley is excited when a model search for a teen magazine takes place at their school, but Mary-Kate is chosen over Ashley.
Ashley makes a new friend, Nicole, which leads Mary-Kate to feel jealousy; Eddie and Kevin argue while Carrie tries to be a mediator.
Mary-Kate, who has had a bad past with animals, gets a homing pigeon which eventually flies away, causing heartbreak to Mary-Kate.
Mary-Kate and Ashley switch costumes with Max and Brian so that they can attend Carrie's Halloween party, from which they were banned by Kevin.
When Kevin starts dating a woman, Marci, they fear that she will replace Carrie. The twins scheme to destroy Kevin and Marci's relationship.
Ashley gets assigned Pokey Valentine, her crush, as a partner on a history project. She becomes jealous when Pokey and Mary-Kate begin spending time together.
Ashley becomes jealous when, during a slumber party, Mary-Kate reveals that she has kissed a boy; After Paul finds out Carrie was over at Kevin's he assumes their relationship is more than it actually is - which leads to rumors about them being a couple.
Kevin hires a tutor for Mary-Kate. Ashley convinces Mary-Kate to switch places so she can flirt with Taylor, the tutor, but their scheme doesn't go as planned; Carrie convinces Kevin to ask out a woman at a coffee shop.
Mary-Kate and Ashley work as matchmakers to get Mrs. Baker and Mr. Fillmore together so that Carrie, a student of Kevin, will be hired as their new baby-sitter.
Two of a Kind is an American sitcom that aired on ABC as part of the network's TGIF line-up, starring Mary-Kate and Ashley Olsen. The show aired from September 25, 1998 to July 9, 1999. The series was produced by Griffard/Adler Productions, Dualstar Productions, and Miller-Boyett-Warren Productions, in association with Warner Bros. Television. It was the last series to be produced by Miller-Boyett Productions in any of its identities.