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 water, and Aileen stops him from drowning by kissing him underwater. Shi-kyung is being 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 learn from her friend that she can drink a potion to “grow” legs. She 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 at his friend’s house in Seoul with other young people.
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 and has a list of must eat food. 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. Hye-young becomes Aileen’s friend and confidant when she discovers her true identity.
Song Jae-rim as Kwon Shi-kyung. A famous chef in the human world. He appear to be cold and arrogant but he suffers from prosopagnosia. Initially, he is not fond of Aileen but he started to fall in love with her when he realized that the person who save him was her.
On Joo-wan as Lee Hyun-myung. He is unable to find a job with his art degree. At the request of his girlfriend Jin-ah, he gives up his pursuit of art and tries to find a desk job. However, he keep facing difficulties in finding a desk job and eventually, his girlfriend left him.
This drama is actually showing the difficulties of university graduates trying to find a job in today’s society. However, if you do not give up, you will eventually succeed. Luckily, the drama is not very “draggy” so it is not that boring.