Chenghai in Linchuan City hides the secrets of the mermaid clan. The ten-year-old mermaid Omega turned into a human and came ashore because of his playfulness and violated clan rules. However, he revealed his true body over time and fell into a coma on the edge of the reef. He was bumped into by a twelve-year-old human Alpha.
After Alpha rescued him, Omega gave him the token Mermaid Heart and promised to go ashore to find him at the age of eighteen. But due to the special restrictions of the mermaid's heart, after the two separated, they completely forgot about each other's appearance, leaving only a vague memory and a vague bond in their hearts.
A few years later, the adult Omega was finally able to go ashore and embark on a journey to find the Alpha. The two met, tested, and got close again and again, but they never recognized each other.
Until the moment Omega took back the mermaid heart, dusty memories came flooding back.
