Legend of the Blue Sea Cast and Characters

Legend of the Blue Sea Cast and Characters

During the Joseon era, a mermaid saves Kim Dam-ryeong from drowning when they were still young. Following the incident, they became friends and Dam-ryeong named her Se-hwa, after his younger sister. They ended up falling in love, but one day Dam-ryeong was forced by his family to marry another girl. Devastated by the news, Se-hwa decides to leave Dam-ryeong forever. Nevertheless, Dam-ryeong's love for Se-hwa forced him to leave his wife and to jump into the ocean to look for the mermaid. The distraught Se-hwa erases his memories of her and their love so that he may not look for her again.

After years of separation, the two grow as adults. Their paths cross again as Se-hwa was found by town folks trapped in a cave after a storm, and was brought to Dam-ryeong, now a town official. Their broken relationship starts back again. On the other hand, a nobleman named Yang made murderous attempts to steal Se-hwa for his own and to overthrow Dam-ryeong. Investigations on the covert killings of some individuals all indicate Yang as the instigator of the crimes. Dam-ryeong also saved a weak Se-hwa from Yang’s concubine who apparently has beaten her to cry since mermaid tears turn into pearls.

Meanwhile, Dam-ryeong keeps on experiencing dreams of himself, Se-hwa, and their foes in the future, and feared that the same ill-fate that afflicts himself and Se-hwa will replay itself. To warn his future self, he commissions a soon-to-be artifact—a time capsule containing a portrait of himself with a message to his future self that “everything is repeating itself” and he has to protect the mermaid from danger, particularly the reincarnations of Yang and anyone related to him. As Dam-ryeong was about to strike down Yang for his crimes, he is arrested for his relationship with Se-hwa and was sentenced to be exiled.

Whilst Dam-ryeong was escorted on boat for his exile, Yang and his associates search for Se-hwa. Urged by his suspicions, he requested the boat to turn around and fought with Yang and his gang. As men aim their harpoons, Dam-ryeong plunges into the water just as a harpoon, hurled by Yang’s son, hits him from behind, saving Se-hwa. To end both of their lives, Se-hwa thrusts the harpoon deeper and stabs herself. The boats sink, carrying Dam-ryeong’s belongings with them, and Dam-ryeong’s jadeite bracelet apparently slides off from the dying Se-hwa’s arm. Yang and his concubine were executed by sword and monkshood poison, respectively, for their crimes.

In the modern days, young Heo Joon-jae runs away from home after the divorce of his parents. His father Heo Il-joong (Choi Jung-woo) adopts stepson Chi-hyun (Lee Ji-hoon) and marries Kang Seo-hee (Hwang Shin-hye). Joon-jae’s mother Mo Yoo-ran (Na Young-hee) works as a housekeeper. In his search for his mother, Joon-jae becomes a con-artist, using his good looks, wits, and skills in hypnotism in conducting scams with his mentor Jo Nam-doo (Lee Hee-joon) and computer hacking genius Tae-oh (Shin Won-ho). His affections are chased after by his college classmate, Cha Shi-ah.

Using the money he earned from his scams, Joon-jae flies to Spain, where he meets a mysterious pretty woman who went inside his hotel room unseen. He calls the police and sends her to jail, but Joon-jae retrieves her after being curious about the jadeite bracelet he saw on the woman’s arm. Nam-doo receives from Joon-jae a photo of the woman with the jadeite and confirms over the phone that the jadeite is genuine and of high price. Meanwhile, Joon-jae is being chased by gunmen being hired by a rich businesswoman who has fallen for Joon-jae’s scams. He brings the mysterious woman with him throughout the pursuit, until they end up cornered on a cliff facing the sea. They jump into the water, and the woman, who was revealed to be a mermaid unbeknownst to Joon-jae, kisses him to erase his memories of her but promises to follow him to Seoul.

Joon-jae returns to Seoul and is tormented by the gaps in his memories and by Jo Nam-doo’s claims of him being with a girl with an expensive jadeite. After months of swimming and traveling, the mermaid also arrives in Seoul wandering around the city, until she runs into Joon-jae. He recognizes her to be the woman Nam-doo is referring to and interrogates her on her identity and why he cannot remember her, although the mermaid hesitates to answer. He brings her to his home and names her Shim Cheong. They live together and steadily gets closer with each other.

Kang Seo-hee hires the fugitive Ma Dae-young (Sung Dong-il) to kill Joon-jae as part of her scheme to inherit Heo Il-joong's fortune. She also has secretly introduced Heo Il-joong with small yet potent doses of anticholinergic and monkshood extract, contributing to his failing health, particularly his vision. Chi-hyun dutifully nurses him, completely unaware of his mother's treachery. Ma Dae-young attempts several times to finish both Joon-jae and Shim Cheong but failed. Shim Cheong uses her power to erase Ma Dae-young's memories and, in the process, learns the sad fate of their Joseon era incarnations Kim Dam-ryeong and Se-hwa.

Linked by dreams, mysterious artifacts, including the jadeite bracelet, a vase with an image of a mermaid kissing a man in modern-day clothes, and the portrait of Kim Dam-ryeong with the inscription “everything is repeating itself", Joon-jae also learns of Dam-ryeong's world and his own fate, concluding that he and Shim Cheong are reincarnations of Kim Dam-ryeong and Se-hwa. Through his consultations with Professor of Neuropsychiatry Jin Kyung-won (Lee Ho-jae), he is able to retrieve his lost memories and the full rendering of his dreams about Kim Dam-ryeong and Se-hwa. He can also hear Shim Cheong's inner voice; he learns that she is indeed a mermaid and that, unless she returns to the sea, her heart will harden and stop beating if he will not love her.

Joon-jae and Shim-cheong lived comfortably with each other despite conflicts and the fear of the impending ill-fate. Joon-jae also finds his mother Mo Yoo-ran, who quit her job as housekeeper. On the other hand, Chi-hyun learns that his real father is Ma Dae-young and he is Kang Seo-hee's lover. He also learns of Kang Seo-hee's crimes and reluctantly consents to them. Kang Seo-hee finally kills Heo Il-joong, using a strong dose of monkshood. Joon-jae, with the help of Shim Cheong, Jo Nam-doo, Tae-oh, and police officer-detective Hong Dong-pyo (Park Hae-soo), busts Kang Seo-hee, revealing her real name to be"Kang Ji-hyun" and her schemes finally revealed. A maddened Chi-hyun steals a gun and aims at Joon-jae but Shim Cheong takes the shot to save him. Kang Seo-hee is detained while Chi-hyun attempts to kill himself with monkshood poison.

As Shim Cheong, being a mermaid, survives the fatal injury, Joon-jae learns that Ma Dae-young is visiting Professor Jin Kyung-won. As Joon-jae, Jo Nam-doo, and Officer Hong Dong-pyo rush to get him, Ma Dae-young recovers his memories of his past life and learns the death of his incarnation, Mr. Yang, and Yang’s concubine, revealed to be by the hands of Park Moo, Jo Nam-doo's incarnation. Just as Professor Jin Kyung-won was about to be murdered, Joon-jae arrives, and Ma Dae-young is seized by the police. Shim Cheong is discharged afterwards, but she still feels pain in her heart due to the gunshot. In order to fully recover, she has to go back into the water. Shim Cheong erases the memories of Joon-jae and of everyone who knew her. Before returning to the sea to recover, Shim Cheong was able to wipe out the memories of all the people she met in Seoul except her child friend named Yoo-na (Shin Rin-ah). Yoo-na shared afterwards that she has been dreaming about her Joseon era incarnation, that she is the daughter of a fisherman and a mermaid, and returns to the ocean.

Three years passed since Shim Cheong left. Joon-jae becomes a prosecutor, Jo Nam-doo works as a lecturer, and Tae-oh is engaged to Cha Shi-ah (Shin Hye-sun). Shim Cheong fully recovers her health and returns to Seoul. Despite his lost memories, Joon-jae recognizes Shim Cheong and it is revealed that he has been recording his life with Shim Cheong in case his memories are lost again. With this, Joon-jae had ultimately accomplished Kim Dam-ryeong’s reminder to protect Shim Cheong from danger and they had evaded the bad fate that had been in store for them. The couple were finally married and lived happily in a home by the sea.



Jun Ji-hyun as Se-hwa / Shim Chung
A mermaid in the Joseon era / A modern-day mermaid who arrives in Seoul to follow her only love, Joon-jae. She has super strength and the ability to read and erase one's memory.



Kal So-won as child Se-hwa




Shin Eun-soo as teenage Se-hwa




Lee Min-ho as Kim Dam-ryung / Heo Joon-jae
The town head and son of a magistrate in the Joseon era who fell in love with a mermaid / A modern-day con-man who uses his looks and wit to transform into different people and conduct scams. He eventually met a mermaid whom he fell in love with again in his present life.




Jeon Jin-seo as child Kim Dam-ryung / Heo Joon-jae




Park Jin-young as teenage Kim Dam-ryung / Heo Joon-jae




Lee Hee-joon as Jo Nam-doo / Park Moo
A con-man and Joon-jae's mentor. He trained Joon-jae to be a great con-man along with him. His Joseon incarnation is Park Moo, who worked with Joon-jae's stepbrother in their past lives. It was later revealed that his loyalty towards Dam-ryung and Joon-jae prevailed over his stepbrother in the Joseon era and modern day respectively.




Shin Hye-sun as Cha Shi-ah
Joon-jae's university junior who has an unrequited love for him, and a researcher at KAIST. Through her job she discovered some artifacts related to Dam-ryung from the Joseon era and helped Joon-jae discover his past identity. She was revealed to be the deceased wife of Dam-ryung in the Joseon era.




Shin Won-ho as Tae-oh
A genius hacker and a con-man together with Joon-jae and Nam-doo. A quiet person who likes to play computer games. He initially has a secret crush on Shim Chung, but ended up falling for Shi-ah.




Lee Ji-hoon as Heo Chi-hyun
Joon-jae's stepbrother. A hardworking son who dutifully stayed by his stepfather's side after Joon-jae left home. His Joseon incarnation was revealed to be an antagonist: the son of Mr. Yang, who killed Dam-ryung and Se-hwa. In his reincarnation, he turned against Joon-jae due to his unrequited love for his stepfather.




Na Young-hee as Mo Yoo-ran
Joon-jae's mother. The Cha family's housekeeper.




Shim Yi-young as young Mo Yoo-ran




Hwang Shin-hye as Kang Seo-hee
Chi-hyun's mother and Joon-jae's stepmother. She will do anything to keep her luxurious life with her son. She hired a hit-man to kill Joon-jae to make her son the definite heir of her husband. Her real name, Kang Ji-yeon, was revealed in the latter part of the series.




Oh Yeon-ah as young Kang Seo-hee / Mr. Yang's concubine




Sung Dong-il as Mr. Yang / Ma Dae-young
A mermaid trafficker during the Joseon era. In the modern day, he is a murder criminal and a hit-man hired by Seo-hee/Ji-hyun to kill Joon-jae. He was later revealed to be Chi-hyun's father.




Choi Jung-woo as Heo Il-joong
Joon-jae's father, and a property agent. After the success of his business he divorced with Yoo-ran and married Seo-hee/Ji-hyun.




Moon So-ri as Ahn Jin-joo
Shi-ah's sister-in-law, a Daechi-dong madam who is vain and haughty. In her past life, she was revealed to be Yoo-ran's servant.




Park Hae-soo as Hong Dong-pyo
A Joseon era government official, who is Dam-ryung's friend. / A modern-day detective who is investigating Dae-young's crimes as well as Joon-jae's scams. Later, he sided up with Joon-jae in investigating the death of Heo Il-joong by the hands of Ji-hyun.




Park Ji-il as Manager Nam
Dam-ryeong's loyal friend in the Joseon era. Il-joong's secretary and Joon-jae's friend in the present time. He took care of Joon-jae when he was still young. In his past incarnation, he discovered the hidden traitors of Dam-ryung, which are Park Moo and the Joseon incarnation of Chi-hyun.




Shin Rin-ah as Seo Yoo-na
Shim Chung's child friend. Apart from Dam-ryung/Joon-jae, she is the only one who can hear Se-hwa/Shim Chung's inner voice both during the Joseon era and present time. In the Joseon time, she was the daughter of a fisherman and a mermaid.




Hong Jin-kyung as Shim Chung's homeless friend
A beggar whom Shim Chung always seeks when she has problems and needs life advice.




Lee Jae-won as Cha Dong-shik
Shi-ah's brother and Jin-joo's husband.




Lee Ho-jae as Professor Jin Kyung-won
A Joseon era fortune teller. A modern-day neuropsychiatrist who helped both Heo Joon-jae and Ma Dae-young in recovering their lost memories.