Netflix’s bubbly K-drama-infused rom-com XO, Kitty is set to deliver its most seismic shake-up yet in Season 3, premiering early 2026, as a long-lost relative emerges not just as family fodder but as an unexpected romantic wildcard that could torpedo Kitty Song Covey’s carefully curated chaos. Following a Season 2 cliffhanger that left fans shipping feverishly over her confession to Min Ho, the spin-off from Jenny Han’s To All the Boys universe introduces a cousin who’s far more than a plot device—he’s the curveball no one anticipated, blending blood ties with butterflies in a way that tests loyalties, ignites scandals, and redefines “forbidden” at the elite KISS academy in Seoul. With production wrapped and post-production humming, whispers from the set promise a summer-soaked saga of revelations, reunions, and reckonings that could either mend Kitty’s fractured heart or shatter it beyond repair.

The renewal news landed like a perfectly timed plot twist on Valentine’s Day 2025, just weeks after Season 2’s January drop skyrocketed to No. 2 on Netflix’s English TV list with 72.1 million hours viewed in its debut week, cracking the Top 10 in 90 countries. Showrunner Jessica O’Toole, who helmed the sophomore outing with executive producer Valentina Garza, teased the extension as a love letter to fans: “If you thought junior year at KISS brought the drama… just wait,” she told Tudum. “Season 3 kicks off with our first summer episode, packed with romance, friendship, adventure—and kissing. Lots of kissing.” Filming wrapped in Seoul by July 2025, after a swift April start, positioning the 10-episode arc for a March 2026 bow—earlier than the 14-month gap between Seasons 1 and 2, capitalizing on the show’s Gen Z grip with its mix of heartfelt Han-isms, K-drama flair, and cultural crossovers.

For the uninitiated dipping into this Seoul soiree, XO, Kitty catapults Kitty Song Covey (Anna Cathcart), the meddlesome matchmaker from the To All the Boys films, across the Pacific on a scholarship to the fictional Korean Independent School of Seoul (KISS). What begins as a tribute to her late mother’s teen exchange evolves into a whirlwind of cultural clashes, queer awakenings, and love polygons that make Lara Jean’s letter fiasco look tame. Season 1’s fish-out-of-water hijinks—think awkward hanbok fittings and a crush on brooding heir Min Ho (Sang Heon Lee)—gave way to Season 2’s deeper dives: Kitty’s bisexual exploration with artist Yuri (Gia Kim), a messy revenge scheme against a scammer ex, a K-pop talent showdown, and a surprise visit from Peter Kavinsky (Noah Centineo) that nodded to TATB roots. The finale detonated with Kitty blurting her feelings for Min Ho amid summer break prep, only for him—scarred by betrayal—to swear off love and jet off with his K-pop star brother Joon Ho. Her bold ask to join his tour? Cut to black, cue the screams.

Season 3 catapults into that unresolved tension, but the real bombshell brewing is the arrival of Kitty’s cousin, reimagined here not as mere comic relief but as “the move no one saw coming”—a charismatic transfer student whose familial revelation upends the academy’s social strata. Sources close to production spill to Deadline that this cousin, played by newcomer Sule Thelwell as the enigmatic Marius, isn’t just popping up for awkward family barbecues; he’s a smooth-talking exchange from the U.S. with a hidden agenda tied to Kitty’s estranged Korean roots, blending charm offensive with subtle sabotage. “Marius rolls in like he owns the place, but his connection to Kitty flips everything,” O’Toole hinted to Variety. “He’s family, sure—but in KISS’s pressure-cooker world, that means alliances shift, secrets spill, and hearts get caught in the crossfire. Fans won’t see this pivot coming.” Early synopses suggest Marius arrives mid-summer, crashing Kitty’s tour escapade with Min Ho and injecting jealousy-fueled drama: Is he protecting family legacy, or pursuing something more personal with Kitty amid her emotional vulnerability?

This cousin bombshell amplifies the love quadrangle’s volatility. Kitty’s confession hangs in the balance as Min Ho grapples with trust issues from his ex Stella’s deceit, potentially pulling away just as sparks fly anew. “Min Ho’s arc is about reclaiming agency after heartbreak—he’s not closing off; he’s recalibrating,” Lee shared with Teen Vogue. “That tour with Joon Ho? It’s his escape hatch, but Kitty tagging along forces the mirror: Does he risk it all for her chaos?” Meanwhile, Yuri’s post-breakup glow-up with ex Juliana (Regan Aliyah)—sparked by Kitty’s meddling letter exposing their kiss—evolves into a tentative friends-to-lovers reboot, complicated by Marius’s outsider allure drawing Yuri into a bi-curious subplot that echoes Kitty’s own fluidity. Q (Anthony Keyvan), Kitty’s ride-or-die bestie, jets to a USC track program but returns for cross-continental cameos, his snarky commentary grounding the frenzy as he navigates his own identity quests.

The ensemble’s expansions add layers of intrigue. Newcomer Soy Kim as Yisoo, a sharp-witted KISS junior with a knack for viral TikToks and underground poetry slams, becomes Kitty’s reluctant summer confidante, unearthing family lore that ties back to her mom’s hidden Seoul diaries. Christine Hwang’s Gigi, a no-nonsense dorm advisor with a soft spot for underdogs, mentors the crew through scandals, while Hojo Shin’s Jiwon—upped to series regular—stirs pot as Min Ho’s scheming tourmate, her envy-fueled leaks threatening to expose Kitty’s cousin conundrum. Returning faves like Dae (Minyeong Choi), the loyal himbo heartthrob; Alex (Peter Thurnwald), the brooding artist; and Madison (Jocelyn Shelfo), the queen bee turned ally, weave subplots of cultural fusion: A summer festival episode blending hanji lantern releases with Fourth of July fireworks, where Marius’s “American edge” clashes with KISS traditions, sparking a campus-wide “Cousin Gate” meme storm.

Beyond romance, Season 3 doubles down on heritage and healing. Kitty’s scholarship renewal locks her in for senior year, but it unearths tensions with her dad back home, prompting virtual therapy sessions that peel back grief layers from her mom’s passing. Flashbacks to Kitty’s childhood visits to Korean relatives—now personified through Marius—reveal suppressed memories of a family rift over cultural assimilation, forcing her to confront if love means compromising identity. “It’s Kitty’s summer of self-discovery, but with higher stakes,” Garza told Forbes. “The cousin isn’t just a twist; he’s the catalyst for everyone questioning ‘home’—in Seoul, in family, in themselves.” Expect K-drama Easter eggs galore: Slow-mo rain confessions, hanbok-to-denim makeovers, and a BTS-inspired idol mentorship that catapults Praveena (Sasha Bhasin) into viral fame, only for jealousy to fracture the friend group.

Cathcart’s Kitty shines as the chaotic core, her wide-eyed optimism masking a storm of insecurities, while Lee’s Min Ho simmers with restrained fire—think brooding stares across tour buses that scream slow-burn payoff. The supporting cast pops: Kim’s Yuri embodies quiet rebellion, Aliyah’s Juliana fierce forgiveness, and Keyvan’s Q delivers laugh-out-loud zingers that cut deep. Thelwell’s Marius, fresh off Saint X, brings a roguish edge—fans on X are already dubbing him “Cousin Crush” in speculative threads, with #XOKittyS3 trending amid theories of a throuple or betrayal arc.

In the crowded YA rom-com ring—flanked by To All the Boys nostalgia and Heartstopper wholesomeness—XO, Kitty distinguishes itself with unapologetic hybridity: Han’s tender multiculturalism meets Korean serial flair, tackling queerness, diaspora, and consent without preachiness. Season 2’s 14.2 million weekend views underscore its staying power, and with O’Toole eyeing a potential Season 4 (no confirmation yet), the franchise feels primed for TATB crossovers—whispers of a Lara Jean guest spot swirl.

As Seoul’s summer sun sets on Kitty’s tour turmoil, one truth endures: Family’s never just blood—it’s the moves that blindside you. Will Marius mend bridges or burn them? Tune in 2026 for the cousin who came to conquer. XO forever.