Cider Melon

Kim Deuk Pal, a 47-year-old gangster and #2 in his gang, dreams of attending university despite his lack of education. After encountering a suicidal high school student, Song Yi Heon, Deuk Pal's spirit possesses Yi Heon's body. Deuk Pal learns that Yi Heon is bullied, leading him to seek revenge on the bullies. In Yi Heon's body, Deuk Pal befriends classmate Choi Se Kyung, a model student hiding his own struggles with domestic violence.

Similar because of censored adaption of same sex work, obsession

Doctor Prisoner centers around an ace doctor in a university hospital’s emergency care center, a skilled professional who treats his patients with full devotion and without discrimination. However, his medical license gets suspended as a result of a medical malpractice incident that arises when the hospital board director causes a ruckus. He then gets his certificate as a medical internist and applies to work at a prison, where his plan is to cozy up to all the bigshots there—business tycoons, celebrities caught for doing drugs, sports stars guilty of gambling—and to win allies, with the ultimate goal of getting revenge against the hospital that ousted him. To do so, he’ll get rid of the existing prison chief doctor and claim the spot for himself.

Revenge, corruption, power scheme are similar themes

Azumi Nayuta is a young prodigy game developer who produces games privately under the name "John Doe" without any link with major company or distributor. Nayuta is often known as the "Banksy of the game industry" as no one knew his true identity, but an incident led him to leave game development. However, the story begins when "Atom", a long-established toy manufacturer that is on the verge of going out of business, begins to search for him in order to rebuild its business.

Kim Sul Woo is a top-secret National Intelligence Service (NIS) agent, known only to a few superiors. When the Songsan Group is identified as a national threat, Sul Woo goes undercover as the elite bodyguard for world star Yeo Woon Guang. Woon Guang, a former stuntman turned top actor, is conceited and brash, often bullying Sul Woo.

Sul Woo's mission involves infiltrating a private party held by Russian tycoon Chairman Victor to extract legendary wood carvings. However, he must also deal with Cha Do Ha, Woon Guang's manager and former fan club head, who is suspicious of Sul Woo and protective of Woon Guang. As Sul Woo navigates his mission, unexpected complications arise from his interactions with Woon Guang and Do Ha, leading to unforeseen developments in their relationships

Baek Chan Mi is a legendary agent for the National Intelligence Service. However, due to an excessive operation, one of her subordinates passes away. After this incident, she takes back all hope of returning to the field when she gets an order to go undercover. She begins working as a secretary for Ilkwang Hitech under the name, Baek Jang Mi. She is joined by a single mother, Im Ye Eun, who has the beauty of a girl group member, and Hwang Mi Soon, a housewife of 18 years whose family believes her to be an insurance salesperson. These three women begin to work together. Meanwhile, Ilkwang Hitech’s CEO, Yoon Seok Ho, knew Chan Mi as his tutor and had a crush on her. He can’t help but think that his new secretary, who looks exactly like his first love but has a different name and age, is a bit suspicious.

Both have NIS agents as main leads who go into undercover after a failed operation

Kim Baek Jin, a respected anchor and leader of the investigative program Argon, upholds a strict standard of verified reporting and journalistic integrity. His team often refers to him as "the Psycho" for his unwavering commitment to the truth. However, when Argon reports on a story that displeases the higher-ups at the broadcast station, the show is relegated to a midnight slot, and Kim loses his senior reporter. Lee Yeon Hwa, an aspiring contract reporter, joins the team to replace him. Despite facing numerous challenges and sabotage from their own company, Argon strives to deliver meaningful and truthful news to the public under Kim Baek Jin's leadership.

My thoughts are both drama revolves around broadcasting industry and investigation programs.

Having started from the bottom and worked his way to the top, Hyeonwoo finds himself betrayed by the royal family of Soonyang Group, the largest corporation in South Korea, after providing 13 years of dedicated service. Just when he thinks all his efforts have been made in vain and prepares to embrace his death, he suddenly wakes up in the body of Dojun Jin, the youngest grandson to the founder and CEO of Soonyang, having traveled back in time. Having been granted this second chance, Hyeonwoo begins to lay the foundation for his revenge against his evil relatives.

my thought is that both hyeonwoo and dong ju are thirsty for revenge after escaping death through second chance against the organization which betrayed them.

Tsuyoshi Nanba (Shotaro Mamiya) is a troubled student, who is good at fighting. His delinquent behavior comes naturally to his family, which includes his parents and two siblings. When his parents were students, they were also trouble makers. Nevertheless, Tsuyoshi Nanba wants to become an ordinary student with good grades. He hides this desire from his family. After he enters high school, Tsuyoshi Nanba begins to lead two different lives. At school, he wears his uniform appropriately and behaves like a model student. At home, he dresses like a delinquent and behaves accordingly.

Tsuyoshi Nanba has now become a top student and has even joined the art club. One day, he sees a student being bullied by other students. Tsuyoshi Nanba changes out of his school uniform and dresses like he does at home. He saves the bullied student. Since then, students at his school talk about the mysterious delinquent student that saved a bullied student. I think both yun gamin and nanba have similar characteristics