Anna Cathcart on 'Creating a New World' in 'To All The Boys' Universe: 'Definitely a Pinch-Me Moment' (Exclusive)

"I think it's one of the most unforeseeable things that has happened in my life," Cathcart tells PEOPLE of returning to her fan-favorite character in the new Netflix spinoff series, XO, Kitty

Sarah Krick
Sarah Krick

Netflix's favorite little sister is back — and this time, she's got her own story to tell.

In XO, Kitty, Anna Cathcart returns to her fan-favorite role of Kitty Song Covey, the self-assured, confident-as-ever little sister of To All The Boys I've Loved Before's Lara Jean (Lana Condor).

However, in the new spinoff series from Jenny Han, fans get to see Kitty set off on her own adventure: a year-long program studying in Seoul, South Korea.

Returning to the character — who she first met as a 13-year-old when she auditioned for the role in 2017 — was "definitely a pinch-me moment," Cathcart, now 19, tells PEOPLE in this week's issue.

"I feel like the best way for me to describe it is like coming back to see an old friend that you haven't seen for a few years," she says. "You're like, 'Oh, oh my God! So good to see you again,' and it's someone you're so familiar with, and someone you know, and someone you love. But then you're also like, 'Oh, it's been many years, I have to relearn parts of you, and there's parts of you that are not the same.'"

Not only had several years passed since she'd finished filming the final installment of the To All The Boys trilogy, which was released on Netflix in 2021, but her own life — as well as Kitty's — had changed during the time away.

"I definitely did not think that I would be a part of this universe and this role for this many years, and to get to explore in the way that I have is something that blows my mind on a daily," she says.

Related:Get a First Look at Netflix's To All the Boys I've Loved Before's Matchmaking Sister Spinoff XO Kitty

The Canadian actress, who just wrapped up her first year at the University of British Columbia, notes that, while XO, Kitty felt familiar in so many ways, it was also a branching out that was "definitely different" than her experience in To All The Boys.

"It's a new extension of this universe that has already existed," she says of the Jenny Han-helmed trilogy. "But it's also kind of creating a new world within that universe."

Familiar or not, it all comes as a shock to her — even now.

"Honestly, none of us expected To All The Boys to become what it did, or to have the reaction that it did," Cathcart admits. "I definitely did not expect it. I think it's one of the most unforeseeable things that has happened in my life. I never would have expected this journey to become what it was."

Netflix / Bettina Strauss
Netflix / Bettina Strauss

The 10-episode spinoff series sees Kitty, who served as Lara Jean's matchmaker when it came to her fairytale love story with Peter Kavinsky (Noah Centineo), exploring her own high school life — and her own love story — as she embarks on a year-long program to study in Seoul, South Korea.

The move — which is almost equally motivated by a desire to share an experience with her late mom, who she discovers attended the same school during a high school year abroad, as well as a need to be with her long-distance boyfriend, Dae (Minyeong Choi) — throws Kitty "upside down into this whole new world she was not expecting to find," Cathcart says.

"What we know [Kitty] to be is very confident in herself, and very sure of who she is, and she kinda feels like she knows what she's doing, and she's always got this — which is something that I've always admired and loved about her," she explains. "But now, for the first time, we're seeing that kind of shift. And she's not so sure all of a sudden, and love is not as simple as she thought it was, and things are not always as clear cut and easy that she pictured they would be."

Cathcart adds, "I really love that part of her story that we're exploring, because it's realistic to growing up."

Park Young-Sol/Netflix
Park Young-Sol/Netflix

Upon arriving at the Korean Independent School of Seoul, or "KISS," as she calls it, Kitty is instantly met with a series of obstacles she hadn't anticipated. The complications only worsen when she finally sees, and surprises, Dae.

"Kitty, at the very beginning, definitely feels like she fully knows what's up. She's like, 'It's us forever. It's us for life. It's just gonna be me and you. We're gonna get married. I know love. This is it. It's great.' She's very decided on that," she explains. "And then immediately when she gets there, within seconds after she first sees [Dae], that's all kind of thrown out the window."

Instead, the teen launches into an exploration of herself, and her mother's history and identity, that she never expected.

"I think it's cool that it wasn't just focused on purely her love life," Cathcart says of the plot. "It's not always just about that. There's so much more to Kitty, and so much more to her story and her life."

Getting to "dive into" her mother's storyline, and explore that more interpersonal relationship, was an added bonus, Cathcart adds.

"She definitely figures things out that she wouldn't have expected and finds pieces of her mom that she wasn't looking for, because she didn't know they were part of her mom's story — which is really special. And I think it's cool just to show that a lot of types of love are important to her, even family love."

Elyse Jankowski/Getty Images
Elyse Jankowski/Getty Images

Related:Lana Condor Is 'Open to Visiting' To All the Boys Again in Spinoff Series: 'I'm a Huge Fan'

As she geared up to move into the driver's seat for the first time, Cathcart says she relied heavily on her To All The Boys co-stars, who had long been "role models" for her.

"Right at the start, when I was hearing about these ideas, I was asking them about advice and telling them about these things that were happening, these different conversations, and they were honestly such a great support system," she says of the cast, which includes Janel Parrish, Madeleine Arthur and Sarayu Blue, along with Condor, 26. "I'm so lucky to have them."

She leaned on Condor in particular, she says, as she navigated the "great things that come with it, the overwhelming things and all the feelings that come with the excitement of being a lead and being at the center of a story."

"I looked up to her for so long that it's wild that I'm in a sliver of the same way experiencing those types of things, too."

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XO, Kitty premieres on Netflix Thursday, May 18.

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