Love alone isn't enough: This fall's K-dramas mix spy thrills, sci-fi and surgical noir

"Just let us fall in love!"

That plea has long since faded into the background. This fall, the protagonists of Korean television are not stealing glances across a cozy café — they are rolling through the gunfire-filled streets of colonial-era Seoul, pulling all-nighters in grease-stained robotics labs and wielding scalpels to tear apart hospital power cartels.

Broadcasters and OTT platforms have upended the playbook for viewers tired of saccharine romance. The result is a genre buffet: love stories remain at the core, but they are now seasoned heavily with espionage, engineering, science fiction and noir. Leading the charge are twenty-something stars Kim Yu-jeong and Kim So-hyun, along with Kim Ji-won and Seo Hyun-jin, who have boldly turned their backs on the romantic comedy.

The defining theme of this fall's drama lineup is the evolution of relationships. Pure romance alone can no longer satisfy an audience conditioned to constant stimulation. Characters must be hurled into extreme settings — the dirt floors of a colonial-era spy war, a cutthroat graduate research lab, a scene of raw physical survival, a cold operating room or an interrogation chamber — before their emotions truly ignite.

Kim Yu-jeong and Kim So-hyun — childhood stars who grew up as the nation's beloved on-screen nieces — are making a long-awaited simultaneous return to the small screen.

Kim Yu-jeong leads tvN's "100 Days of Lies," which premieres Saturday, playing Lee Ga-gyeong, the finest pickpocket in colonial Seoul and a secret agent for the independence movement. The spy romance unfolds as she becomes entangled with Kim Tae-woong (played by Park Jin-young), an elite interpreter for the Japanese Government-General. Once known for delicate Sageuk drama roles, she reinvents herself as a nimble operative diving straight into the heart of enemy territory.

At a press event in Yongsan, Seoul, on Tuesday, Kim Yu-jeong said the two central characters share a sense of uncertainty about their own futures. "Ga-gyeong is a young person who doesn't yet know what dreams to chase, and Tae-woong is someone struggling with his own identity," she said. "It's a romance about two people who meet, feel each other out and grow together. There were moments that were hard to navigate alone, but on set we had a connection — just one look was enough."

"100 Days of Lies" is set in 1932 colonial-era Seoul. The romance between the two young leads is woven through with the broader conflict between an armed anti-Japanese resistance group and the Japanese Government-General, giving the drama its historical backbone.

Director Yoo In-sik said the series carries a passionate and noble cause at its heart, but promised viewers plenty of intrigue along the way. "As you follow each character, you'll find stories packed with espionage, romance and all kinds of excitement," he said.

Kim So-hyun strips away all campus romance in ENA's "Doctor of Love," which premieres Monday. She plays Yoo Jin, a master's student who spends her nights getting grease on her hands in a corner of a graduate research lab alongside a doctoral candidate who has lost one leg (played by Chu Young-woo). Love blooms amid the brutal realities of thesis deadlines and a bleak job market — a bond forged less in candlelight than in the trenches of shared exhaustion. The series is the final work of director Ahn Pan-seok, who died last August. Under his hyper-realist lens, Kim So-hyun draws out the most unvarnished portrait of youth with quiet restraint.

The script was written by Min Hyo-jeong, known for "Rooftop Cat" and "Full House." Min described the drama as a romance centered on graduate students at a prestigious university. "The joy and despair of doctoral students who know nothing about dating — that's the charm and the fun of our show," she said. "These are people so afraid of failure that they cannot even try, who worry about tomorrow's misfortune and give up today's happiness. You'll laugh and cry at their painfully real everyday lives and their love story."

Romantic imagination can even rewrite the laws of physics. Netflix's "Charge Me Up," starring Chae Soo-bin, takes the dopamine-fueled romantic comedy to its logical extreme. The series is adapted from a web novel of the same name.

The setup: a terminally ill third-generation chaebol heir (played by Kim Young-gwang) whose artificial heart battery is running dangerously low, and a writer (played by Chae Soo-bin) whose body conducts electricity — shocking anyone she touches. The show plays their forced proximity for comedy, framing their survival as a darkly funny physical crisis: a man who needs to live and a woman who could kill him with a touch. Its greatest strength is the wit with which it smashes the worn-out "fated encounter" cliché by grounding it in the literal laws of electricity.

Pink-tinted romance is not the only option this season. Kim Ji-won and Seo Hyun-jin — both once crowned queens of the romantic comedy — are shattering that image entirely.

Kim Ji-won goes dark in SBS's Friday-Saturday drama "Doctor X: Age of the White Mafia," premiering Friday, playing Gye Su-jeong, a surgical genius who tears apart a powerful hospital cartel with her scalpel. Rather than chasing love, she squares off against seasoned heavyweights Son Hyun-joo and Lee Jung-eun in a blood-soaked power struggle, positioning herself as the undisputed dark hero of a cold medical noir.

"Doctor X" is a remake of the Japanese Asahi TV drama "Doctor-X: Surgeon Michiko Daimon," a hit series that ran for seven seasons. The line "I never fail" became a cultural catchphrase in the original — and viewers will now hear it from Kim Ji-won.

Director Lee Jeong-rim praised Kim's performance. "Kim Ji-won moved convincingly between the commanding presence she projects in the operating room and the quirky, deeply human side of Gye Su-jeong outside it — the gap between the two is enormous," Lee said. "The doctors who came to consult on the surgical scenes actually applauded on set."

Seo Hyun-jin's choice, MBC's "Liar," defies audience expectations in a different way. She and Yoo Yeon-seok — who reduced viewers to tears together in the 2016 drama "Romantic Doctor, Teacher Kim" — reunite after a decade, but this time they are not holding bouquets. They are holding knives of suspicion. The two face off in a psychological thriller in which a single disputed memory has each accusing the other of lying. The tension that replaces the romance is what will steal viewers' hearts.