He Comes From the Abyss

Wei Xiran faked being a playboy for ten years to seize her family business, only to flash marry mysterious merman Shen Zhi-Nian due to a conspiracy. Shen Zhi-Nian, a thousand-year-old merman who broke his promise to his past lover, brings a mind-reading, fish-controlling baby to find his wife for a hundred years. After Wei Xiran discovers her husband's scales, the truth of the century-old broken promise emerges, while villain Lin Xu-Bai closes in step by step. From a contract to true love, the couple fights the conspiracy together, launching a deep-sea romance spanning a hundred years.