Circle, also known as Circle: Two Worlds Connected is a 2017 Korean Drama that aired on tVN.
The drama is divided into two parts. The first is set in the present, The Beta Project (2017); which revolves around twin brothers who think they saw an alien in their childhood. In the present, the younger brother, Kim Woo Jin is a university student, and his elder brother Kim Bum Gyun, was recently released from jail, having been incarcerated for causing someone's death, because he thought the person was an alien. Bum Gyun is convinced that the alien who they met in their childhood is the one who caused their father to disappear and is also the reason behind a spate of student suicides at Handam University. Woo Jin is not inclined to believe him, until he and his brother spot a girl, Han Jung Yeon, who looks exactly like the alien from their childhood. Suddenly, everything seems to be connected, including the suicides and the brothers and Han Jung Yeon work towards uncovering the reason behind the university suicides, unravelling a bigger mystery in the process.
The second setting is set in the future, A Brave New World (2037). The story is about an alien invasion in 2017 and the subsequent new Earth in 2037; which is separated into the "Smart Earth" where people's emotions are controlled and no crimes or illness exist, and "General Earth" where people still suffer from rampant plague and lawlessness. Kim Joon Hyuk, a violent crimes detective who lives on General Earth and is skeptical of Smart Earth. However, he believes that his missing brother is on Smart Earth and is able to gain entrance into Smart Earth, when a sudden murder shocks the crime-free utopia that is Smart Earth. Once on Smart Earth, he discovers that everything is not what he seems and that maybe, the disappearance of his brother is linked to the corporation that controls Smart Earth, Human B.
The drama stars Yeo Jin Goo as Kim Woo Jin, Gong Seung Yeon as Han Jung Yeon, Kim Kang Woo as Kim Joon Hyuk, An Woo Yeon as Kim Bum Gyun , Jung In Sung as Park Min Young and Lee Gi-kwang as Lee Ho Soo.
This series provides examples of:
- The Ageless: Byul counts. She retains the same appearance throughout the series.
- Amnesiac Hero: Joon Hyuk reveals in the third episode that he lost all of his memories before. It's later revealed he's actually Bum Gyun who lost his memories. And Jan Yeon is actually an amnesiac Byul.
- Arc Words: Bluebird. The word is repeated many times in both settings of the drama for different meanings.
- The Atoner: Bum Gyun as Joon Hyuk is very regretful over not abandoning his obsessive search for aliens which lead to his brother's disappearance.
- Big Bad: Overall Park Dong-gun. While Han Yong-woo starts as the Big Bad for Beta Project, Dong-gun takes over and stays that way in the Brave New World.
- Call-Forward: Due to the nature of the series, a lot of plot points in the Brave New World are used in the Beta Project or vice versa.
- Jung Yeon calls herself a hacker in 2017 while her method of "hacking" is simply placing a camera in front of a computer, by 2037 she's the best hacker in the world.
- Jung Yeon and Joon Hyuk talk about how Joon Hyuk lost his memory and Woo Jin's reaction.
- Jin-Hong mentions that he was part of the cyber force in one episode during Brave New World. The last episode shows him being transferred to that department due to his refusal to listen to orders.
- Jin-Hong draws a web comic in the Brave New World, which shows his art skills which give him the hint that Park Dong-Gun isn't what he seems.
- Came from the Sky: One of the very first scenes of the drama features what seems to be a very bright ball of light hurtling towards the ground. From the ball of light, emerges a naked woman, who immediately collapses at the feet of Woo Jin, Bum Gyun and their father, Kim Gyu Chul.
- Disappeared Dad: Woo Jin and Bum Gyun's father left them in childhood with Byul.
- Emotionless Girl: Byul never shows any emotions and seems confused over them. Averted after she lost her memories and took the name Jung Yeon.
- FaceHeel Turn: Park Dong-gun was at first horrified when he learned what his old friend Han Yong-woo was doing to the students in their college. But after he realized what Yong-woo was after, he quickly became as obsessed as his friend and even took his place.
- Family of Choice: The main four. Only Woo Jin and Bum Gyun are related. However, throughout the course of the drama, we see that Jung Yeon and Min Young have become an integral part of the twins' lives.
- Fire-Forged Friends: At first Joon Hyuk and Lee Ho-soo disliked each other intensely. They became true friends when Hoo-soo realized that Human B was wrong and changed sides.
- Foregone Conclusion: Due to how the drama is structured, we know in 2017, Bum Gyun, Min Young and Jung Yeon will survive as they appear in 2037 and that Won Jin will find Bum Gyun.
- Both Min-young and Joon Hyuk have a scar behind their left ear. This hints that Min-Young also had a worm in her brain.
- In one episode of the Brave New World, Park Dong-gun talks about a law to make human cloning legal. Which makes sense when you realize he had a dying Woo Jin cloned.
- HeelFace Turn: When Hoo-soo realized that his memories were blocked at first he is desperate to escape the pain by having them blocked again. But when he sees that the man that caused his girlfriend to commit suicide is not only happy but doesn't have a clue over what he did, Hoo-soo realizes that Human B is wrong.
- Human Aliens: Byul looks exactly like a young woman in her early twenties. She can even converse in Korean. The only indication that she is not quite human is the fact that she is expressionless, emotionless and cannot process emotions or feelings.
- I Will Find You: One of the running themes of the drama is Woo Jin and Bum Gyun looking for each other, in different decades. In the future, Han Jung Yeon is looking for Woo Jin as well.
- Just Think of the Potential: Han Yong-woo and later Park Dong-gun think of Byul's system that allows humans to see memories as video files and edit them.
- Living Emotional Crutch: Woo Jin and Bum Gyun are this to each other as they're the only family they have left.
- Maybe Ever After: For Joon Hyuk or Bum Gyun and Park Min-young. And Woo Jin and Jung Yeon.
- Missing Mom: Woo Jin and Bum Gyun's mother died when they were very young to the point that 11 year old Woo Jin didn't remember her face anymore.
- Misunderstood Loner with a Heart of Gold: Woo Jin is hated in his college as he refuses to participate in their school-wide ban which they see as him being selfish. In reality, he needs the money to pay for his ill grandma and he's a scholarship student.
- Mr. Fanservice: Do we need a scene featuring a shirtless and buff Woo Jin? Not necessarily, but the audience is rewarded with one.
- Orphan's Plot Trinket: Jung Yeon has a star charm that she made with her mother and the only thing left of her as she lost her memory. It's revealed to be a lie as Woo Jin gave it to her 10 years ago and is what clues her to her turn identity.
- Polar Opposite Twins: Woo Jin and Bum Gyun couldn't be anymore different, when they were kids, Woo Jin believed in aliens while Bum Gyun was more grounded in logic. In 2017, it's reversed with Woo Jin being enrolled in a science college while Bum Gyun is obsessed with catching aliens.
- Properly Paranoid: Bum Gyun thinks that the suicides in Woo Jin's college aren't suicides and that Jung Yeon is an alien. It's later reveals he's totally correct.
- Ship Tease: The drama has quite a few moments between Woo Jin and Jung Yeon. Bum Gyun and Min Young share some ship tease as well.
- Red Herring:
- At first we're lead to believe that Joon Hyuk is Woo Jin due to their similar mannerisms but it's actually revealed it's Bum Gyun.
- We're given a lot of evidence that Woo Jin might be the chairman of Human B due to having the photo that Bum Gyun took of them, his own beliefs that to treat PSTD is to make them forget and a photo of him standing in front of a painting in the chairman's office. Turns out it was Park Dong-gun all along.
- Took a Level in Badass: Hoo boy did the Time Skip do wonders for some people.
- Bum Gyun is an alien obsessed young adult that was captured pretty easily in 2017. As Joon Hyuk, he's an iron willed detective that is a capable fighter and dedicated to finding Woo Jin.
- Jung Yeon was a regular girl in 2017. In 2037, she's a legendary hacker that many aren't sure even exists and is able to easily hack Human B.
- Troubled, but Cute: Applies to both Woo Jin and Bum Gyun. Bum Gyun just finished a stint in prison and Woo Jin is a college student who does not seem to have a good relationship with anyone.