There is a metaphor that defines the new, dark offering from Netflix Taiwan. It begins with a moth. “Moths are nocturnal,” a voice explains. “They use the moon to navigate… They think the light is the moon… They don’t know that, no matter how hard they try, they are just going in circles.” It’s a poetic image that turns tragic, as the series’ protagonist, Li Jen-yao, describes himself in precisely that way: as a “moth chasing the sun.”
The series, a “dark mystery romance” titled Had I Not Seen the Sun, establishes its premise with the force of a gut punch. Li Jen-yao, a 25-year-old played by Tseng Jing-hua, turns himself in to the police and confesses. This is no ordinary crime. He admits to being the “Rainstorm Killer,” a serial murderer who, years prior, terrorized and murdered several of his high school classmates.
The story kicks off with its central mystery: Jen-yao confesses to the gruesome details of his crimes but systematically refuses to reveal his motive. The narrative is anchored in the violent contrast between the apparently innocent boy from the past and the cold-blooded killer of the present. We see a flashback: Chiang Hsiao-tung (Moon Lee) dances ballet on a rooftop, like a “fragile butterfly,” while a young Jen-yao watches her. The scene cuts abruptly to Jen-yao in the present, dressed in a black raincoat, as news reports identify him as a ruthless killer who even murdered his own father.
The original title, Rúguǒ Wǒ Bùcéng Jiànguò Tàiyáng (If I Had Not Seen the Sun), stops being poetic and becomes the series’ thesis. The moth (Jen-yao) is a creature of the night. The butterfly (Hsiao-tung) is the “sun.” The title is a conditional question suggesting the tragedy became “irreversible” the moment the darkness became obsessed with the light. The romance is the direct cause of the dark suspense.
The Protagonist: The Evolution of Tseng Jing-Hua
The actor bringing this complex “Rainstorm Killer” to life, Tseng Jing-Hua, is no stranger to high school trauma or intense romance. His career has been defined by navigating precisely these extremes, solidifying him as one of the key figures in the new wave of Taiwanese film and television.
His career launched meteorically with his film debut, the acclaimed supernatural horror thriller Detention. It was no ordinary casting: he was selected from over ten thousand hopefuls for the role of Wei Chung-ting. The impact was immediate. His very first performance earned him a prestigious Golden Horse Award nomination for Best New Performer.
He then cemented his status with a culturally defining role in recent Taiwanese cinema: “Birdy” in Your Name Engraved Herein. The film broke barriers, becoming the highest-grossing LGBT feature film in Taiwan’s history. Although the story was told from his co-star’s perspective, Tseng’s character was the central enigma. His performance required him to convey deep love and painful conflict almost entirely implicitly, through nuances and facial expressions that generated intense analysis from audiences.
His versatility was proven when he jumped to the fantasy-comedy Oh No! Here Comes Trouble, where he played the protagonist Pu Yi-yong, a role that also garnered him award nominations. With a range that also includes work like Eye of the Storm, Hello Ghost, and appearances in series like The Victims’ Game, Tseng Jing-Hua has specialized in complexity.
This new role as Li Jen-yao in Had I Not Seen the Sun is not a deviation, but a perfect synthesis of his career pillars. It combines the psychological horror and “high school trauma” that defined Detention with the tragic, intense “forbidden romance” audiences associated with Your Name Engraved Herein. The series’ own description, “a transition from a campus youth romance to dark suspense,” seems to mirror the duality Tseng has proven he can master.
Unraveling the Mystery: The Plot and Its Key Players
The series isn’t focused on a simple “whodunit,” but a profound “whydunit.” The narrative device for exploring this is Chou Pin-yu, an aspiring documentarian (played by Chiang Chi). In prison, Li Jen-yao refuses all visitors and press—except for her. He agrees to grant her his first and only interview.
But Pin-yu’s encounter with the killer soon drags her into something beyond a simple interview. As she progresses in her conversations with Jen-yao, Pin-yu begins to find herself “entangled” in the case in a personal and dangerous way. This is where the series introduces its most intriguing element: the fusion of reality and illusion. Pin-yu starts having “unsettling dreams.” In them, she sees the mysterious schoolgirl from the rooftop and has what are described as “intimate, ambiguous encounters” with the killer himself. The plot becomes a psychological labyrinth where the lines between present and past, reality and dream, blur, as buried secrets about “love, hatred, guilt, and redemption” begin to resurface.
The epicenter of it all is the “butterfly” from the rooftop, Chiang Hsiao-tung, played by Moon Lee. She is the “sun” that the “moth” Jen-yao was chasing. But this isn’t the first time Lee and Tseng have explored horror in high school hallways. Both actors previously shared the screen in Detention. What’s more, both are also “alumni” of another acclaimed Netflix thriller, The Victims’ Game. This casting, which reunites key players from Taiwan’s prestige thrillers, suggests a deep understanding of the chemistry needed for a story of this caliber.
The series’ philosophy, articulated by its creators, revolves around the theme of “irreversibility.” Director and screenwriter Chien Chi-feng explained it this way: “Growing up, we were taught that wounds heal with time. However, as we get older, we realize that many wounds are irreversible and cannot heal.” The series, therefore, seeks to “embrace every life that has been hurt.”
The Seal of Quality: The Creators of ‘Someday or One Day’
For fans of Taiwanese drama, Had I Not Seen the Sun comes with a top-tier production pedigree. It arrives from the “award-winning creative team” behind the cultural phenomenon Someday or One Day.
That series redefined expectations for Asian drama, masterfully blending romance, comedy, a murder mystery, and a complex time-travel plot. The fact that writers Chien Chi-feng and Lin Hsin-huei are reuniting for this project sets a very high bar for narrative complexity.
This new project marks two milestones for the team: it is their first collaboration on a streaming platform and it marks the directorial debut of Chien Chi-feng, who co-directs with acclaimed filmmaker Chiang Chi-cheng. The team has mentioned that the creative freedom of streaming has allowed them to “tackle dark and heavy themes that are rare, or even non-existent, on traditional platforms.” It’s the logical evolution of their style: taking the angst and complex romance they explored in Someday or One Day and pushing it into darker, more adult territory.
The “powerhouse cast” is rounded out by actors like Lyan Chen, Umin Boya, Yao Chun-yao, and Shih Chih-tian.
The Encounter with Darkness
Had I Not Seen the Sun is shaping up to be a dark cocktail of genres. It’s a psychological thriller about the motives of a serial killer, a tragic romance about a youthful love gone catastrophically wrong, and a surrealist drama where dreams and reality collide.
It’s a story that, according to its star Tseng Jing-hua, “conveys the profound experiences of emotional separation, as well as healing and forgiveness,” and will take the audience through “emotional highs and lows, embodying both light and darkness.”
The series is set to be released in a two-part format. Part one of Had I Not Seen the Sun arrives on Netflix on November 13.
