TORONTO — "Degrassi" marks a decade of unexpected pregnancies, underage drinking, broken hearts and general angst-ridden rebellion with a new season Monday that introduces its first transgender character.

The Canadian teen drama promises to enter uncharted ground with a storyline in which a new student, Adam, presents himself as a boy even though he was born a girl.

"I can truly say that when we decided to do this episode we realized this is brand new territory for us," says producer, director and actor Stefan Brogren, whose character Mr. Simpson returns as school principal.

"We've never even tried to breach this subject before. Of course we've dealt with gay and lesbian stories but you can't approach this the same way."

The new student is played by former "Life With Derek" star Jordan Todosey, a bubbly 15-year-old who says she had to chop off long blond locks, darken her hair and adopt a more boyish swagger to pull off the role.

"The writing is good, they really go there with that kind of stuff and I think that this character can really speak for anybody who is outcast or bullied or transgender or anything like that," Todosey said from the Toronto set earlier this year, after shooting a violent confrontation with school bullies.

"I really hope the fans like Adam."

Such delicate topics are certainly not new for the long-running franchise, which began as "The Kids of Degrassi Street" in 1980, and was followed by "Degrassi Junior High," "Degrassi High" and "Degrassi: The Next Generation."

"Degrassi High" famously sparked controversy in the United States when a pregnant character battled past protesters at an abortion clinic. Canadian viewers saw the full episode but U.S. viewers got an edited version that left it unclear whether she went through with the procedure.

This time, the transgender storyline is expected to get prominent play on both sides of the border, airing on TeenNick at the same time as the Canadian broadcast on MuchMusic.

Brogren says great effort was made to handle the transgender storyline with care, with writers going so far as to consult with various advocacy groups to make sure the issue was presented accurately.

"It really sort of threw us for a loop because the writers did some amazing research, both networks have been in touch with gay, lesbian, transgender organizations to make sure they like the script. We want to make sure that we're not hurting the subject matter," he says.

"This will be an ongoing character, this will be someone who'll be around his whole high school experience, so we want to make sure that this character is loved (and) develops a fanbase."

The National Center for Transgender Equality defines transgender as an umbrella term that refers to people "who live differently than the gender presentation and roles expected of them by society."

Todosey says she expects the heavy topic to resonate with kids, even though it's a rarely discussed issue that even adults have trouble understanding.

"It's well-written. I feel like it really does speak to kids and I think it's a great role to really open up, show people what transgenders are like," she says, describing her character as someone who "was born physically as a girl but between the ears, he feels like he's a guy."

"It lets the audience walk a mile in the character's shoes and that's really good."

Things come to a head for Adam in episodes set to air Aug. 11 and 12, when the school discovers Adam's secret. The episodes also feature ballroom dancer and "So You Think You Can Dance Canada" judge Jean-Marc Genereux in a guest role.

"Degrassi," which was previously titled "Degrassi: The Next Generation," kicks off its 10th season Monday with a special summer schedule that will see the first 24 episodes air four days a week, with a two-hour marathon of repeats each Friday.

"It's an experiment. We know that the kids can't get enough of the show. And (TeenNick) asked us, 'Do you think this is possible?"' explains Brogren, adding that the series returns to a weekly schedule in September.

"It changes how we write scripts, how we shoot them and you're getting a lot more of an elongated story throughout those 24 episodes. We don't want to call it a soap opera, but it definitely has a lot more cliff-hanger going on."

The new season will be preceded by the TV movie "D:NYC -- Degrassi Takes Manhattan," airing Friday on MuchMusic.

Cameos in the film include Mary Murphy of "So You Think You Can Dance," MTV Canada host Jessi Cruickshank, "Canada's Next Top Model" host Jay Manuel and comic Colin Mochrie.

Other new cast members to join season 10 of "Degrassi" include Munro Chambers as the eccentric Eli, who hides a dark past; Luke Bilyk as Adam's homophobic step-brother Drew; and Alicia Josipovic as the tough Bianca. "Instant Star"'s Cory Lee also joins the cast as the media immersion teacher.