Netflix’s latest Taiwanese drama Had I Not Seen the Sun is now complete. This dark mystery series comes from the award-winning team behind Someday or One Day and is drawing viewers in with its story of trauma and crime. The show split its 20 episodes into two parts. Part one became available on November 13, 2025, and the second part, concluding the story, was released on December 11, 2025.
The series follows a young man named Li Jen-yao who shocks everyone by confessing to a series of murders. He gives himself up to the police and admits to killing several of his former high school classmates. This act earns him the grim nickname “Rainstorm Killer” in the media. While in prison, he agrees to be interviewed for a documentary by a research assistant named Chou Pin-yu. Her investigation starts to connect dreams, distorted memories, and hidden truths from the past. A mysterious girl from Jen-yao’s school days also appears to be key to unlocking the real story.
The Creative Team and Story Origins
This new series is a major project for its creators. It is produced by the same team responsible for the globally popular Taiwanese drama Someday or One Day. The show’s producer, Ma Yi-ting, shared that the idea for this dark story actually came to her before they began filming Someday or One Day in 2019. At that time, many popular shows featured light-hearted romance and idealized male characters.
Instead of following that trend, the team decided to go in a different direction. They wanted to create a main character marked by deep tragedy and pain. The writers conducted extensive research, including interviews with lawyers, to ground the difficult events of the story in real-world cases. The directors explained that the core theme of the story is “irreversibility”—the idea that some wounds never fully heal.
“Had I Not Seen The Sun is a story built around the theme of ‘irreversibility.’ Growing up, we were taught that wounds heal with time. Yet as we get older, we realize that many wounds are irreversible and cannot be healed,” explained director and writer Chien Chi-Feng.
The Main Cast and Their Challenging Roles
The show features a talented cast taking on complex and emotionally demanding roles.
- Tseng Jing-hua as Li Jen-yao: Tseng plays the central character, the so-called “Rainstorm Killer.” This role is a significant change for the actor, who is often seen in more gentle or romantic parts. He portrays Jen-yao both as a troubled high school student and as the confessed murderer he becomes. Tseng said that getting into the character’s mindset was a process. At first, he felt nervous, but as filming went on, he began to understand the character’s emotional numbness.
- Moon Lee as Chiang Hsiao-tung: Lee plays a bright ballet dancer from Jen-yao’s past named Chiang Hsiao-tung. Her character is described as someone with a sunny, straightforward personality who tries to help Jen-yao during a difficult time. Lee prepared for three months to learn ballet for the role. She described the project as “the warm and gentle sunlight after days of winter rain”.
- Lyan Cheng and Chiang Chi in Supporting Roles: The cast is rounded out by strong performers like Lyan Cheng, who plays Lai Yun-chen, a friend caught in the middle of the story. Chiang Chi plays the documentary assistant Chou Pin-yu, whose investigation drives much of the plot in the present day.
Genre and Style: More Than Just a Crime Thriller
While the story begins with a murder confession, Had I Not Seen the Sun blends several styles. It is officially listed as a crime drama, thriller, and romance. The narrative moves back and forth in time. One timeline shows Jen-yao’s difficult high school years, which play out like a tragic coming-of-age romance mixed with elements of bullying and family strife. The other timeline follows the documentary interview in prison, which takes on a psychological and almost supernatural tone as the investigator experiences strange dreams and visions.
This mix means the pace of the show is deliberate. It builds tension through character psychology and the slow reveal of secrets rather than through action scenes or sudden shocks. The directors use visual symbolism, contrasting light and dark imagery to reflect the themes of the story. A key symbol in the show is the moth, representing a creature drawn to a light that will ultimately destroy it.
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Who Is This Show For? A Viewer’s Guide
Deciding whether to watch Had I Not Seen the Sun depends largely on what you enjoy in a series.
You will likely enjoy this show if you:
- Appreciate slow-burning, character-driven mysteries.
- Enjoy stories that use timelines to unravel a puzzle.
- Are interested in complex themes like psychological trauma, guilt, and the long-term effects of bullying.
- Are a fan of the creative team’s previous work on Someday or One Day.
- Don’t mind content that deals with heavy emotional subjects.
This show might not be for you if:
- You prefer fast-paced, action-oriented thrillers.
- You are looking for light, easy-going entertainment.
- You are sensitive to scenes or stories involving violence, bullying, or trauma.
The show carries a TV-MA rating in the United States for a reason. Parents should note that guides describe its violence as “severe” and its profanity as “moderate”. It has mature ratings around the world, such as 18+ in the UK and MA15+ in Australia.
Final Release Details and Where to Watch
The full first season of Had I Not Seen the Sun, consisting of 20 episodes, is available to stream globally only on Netflix. The release was structured in two batches:
- Part 1 (Episodes 1-10): Released on November 13, 2025.
- Part 2 (Episodes 11-20): Released on December 11, 2025.
Filming took place in various locations across Taiwan, including Taichung City, adding a specific local atmosphere to the story.
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