The Idle Mermaid (; literally Surplus Princess) is a 2014 South Korean romantic comedy television series starring Jo Bo-ah, On Joo-wan, Song Jae-rim, and Park Ji-soo. A modern retelling of the 1837 fairy tale "The Little Mermaid" by Hans Christian Andersen, it aired on tvN from August 7 to October 9, 2014 on Thursdays at 23:00. Originally slated to run for 14 episodes, the total number of episodes was reduced to 10. The series inspired an unofficial Indonesian adaptation called Mermaid in Love. Series overview Aileen is a mermaid princess who is in love with Kwon Shi-kyung, a human celebrity chef. While recording a TV show next to the Han River, Shi-kyung hits his head and falls into the river, and Aileen stops him from drowning by kissing him underwater. Shi-kyung is pulled out from the water by Yoon Jin-ah, an intern who works for and is also in love with Shi-kyung. In order to meet Shi-kyung again, Aileen steals a magic potion from the male witch Ahn Ma-nyeo, and is transformed into a human girl. It's only after her transformation that Aileen learns that she has 100 days to find true love, or else she will die and turn into bubbles. Ahn Ma-nyeo helps Aileen by setting her up with the fake identity of "Kim Ha-ni," and sends her to live in a house in Seoul with other young people, most of whom are unemployed and searching for jobs. Among Aileen's new housemates is Lee Hyun-myung, Yoon Jin-ah's ex-boyfriend who is trying to win her back. With her new friends to help her, Aileen vows to find a way to win Shi-kyung's love, but in the end she falls in love with Hyun-myung. Although she initially disappears once her 100 days are up, she returns a year later to see her friends again. Cast Principal Jo Bo-ah as Kim Ha-ni/Aileen The eighteenth mermaid princess of a mermaid kingdom in the sea. She finds a smartphone that fell into the sea and uses it to surf the internet and learn about the human world. She becomes infatuated with chef Kwon Shi-kyung; after saving him from the Han River, Aileen decides to become human so that she can be with him. On Joo-wan as Lee Hyun-myung A human and resident of surplus house, he is unable to find a job with his art degree. At the request of his girlfriend Jin-ah,