The little mermaid turned into a childhood sweetheart of a wealthy family

Yu Xi is a six-year-old boy who is actually a mermaid from a children's storybook. Born prematurely and suffering from a congenital illness, he spent his early childhood in an underwater hospital. After a high fever, he fell asleep beside a storybook and woke up in the human world as a healthy child. He has no memory of his past life as a mermaid, but retains an instinctive love for water and a naive, innocent worldview. His parents, who recently returned from overseas, move into a luxury villa next door to the wealthy Gu family. Yu Xi’s first day in this new environment leads him to discover a private swimming pool, which triggers his curiosity and desire to swim.

Gu Beilu is the young master of the Gu family, a child with exceptional intelligence but severe mysophobia, or an extreme fear of germs. He is aloof, dislikes physical contact, and has no friends his age. Secretly, he is also a programming prodigy who hides his activities from his overbearing parents. When Yu Xi accidentally discovers Gu Beilu hiding in the pool lounge, the two boys form an unlikely bond. Yu Xi, unaware of Gu Beilu’s reputation, treats him with genuine kindness and sincerity. He tends to Gu Beilu’s minor knee wound and shares his food, breaking down the boy’s defensive walls. Gu Beilu, in turn, finds himself inexplicably drawn to Yu Xi’s warmth and lack of fear.

The core conflict arises from Gu Beilu’s decision to hide his true identity from Yu Xi. He adopts the alias "Derek" to interact with Yu Xi without the pressure of his family name or social status. This deception creates a complex dynamic where Yu Xi admires Gu Beilu as a distant, kind figure while bonding with "Derek" as his best friend. Gu Beilu struggles with jealousy and possessiveness, wanting to be both the admired classmate and the intimate friend. Meanwhile, Yu Xi’s parents arrange for him to take swimming lessons at the Gu residence, further intertwining their lives.

A pivotal turning point occurs during a beach trip. Yu Xi gets lost while searching for shells to give to both his friends, Derek and Gu Beilu. Gu Beilu, realizing the danger his lie has caused, panics and helps organize the search. When Yu Xi is found safe, Gu Beilu confesses that Derek and Gu Beilu are the same person. Instead of being angry, Yu Xi is delighted, seeing it as proof that both versions of his friend are kind. This incident deepens their bond but also highlights Gu Beilu’s growing anxiety about losing Yu Xi.

As the story progresses, the two boys prepare for elementary school. They discover they will be in different classes, which distresses Gu Beilu. He becomes overly protective, insisting Yu Xi join his advanced class and constantly drilling safety rules into him. Despite his mysophobia, Gu Beilu allows Yu Xi to touch him, feed him, and stay close, signaling a significant transformation in his personality. The narrative follows their daily interactions, highlighting Gu Beilu’s internal conflict between his need for control and his desire for connection, while Yu Xi remains blissfully unaware of the complexities surrounding his new friend.

The story direction points toward the challenges of their growing friendship as they navigate school life. Gu Beilu’s protective nature may clash with Yu Xi’s independent and social spirit. The secret of Yu Xi’s mermaid past remains hidden, but his innate connection to water continues to influence his actions. The narrative explores themes of trust, identity, and the healing power of childhood friendship, as Gu Beilu learns to open up to the world through Yu Xi’s innocent perspective.