A water-phobic teacher is saved by a mermaid and accidentally swallows her magical pearl, trapping her on land. She enrolls in his school to retrieve it, and they fall in love, but their romance is threatened when the school principal uncovers her secret.
| Actor | Role |
|---|---|
 Christy Chung Lai-TaiMermaid | Mermaid |
 Ekin Cheng Yee-KinSiu Chi | Siu Chi |
 Teresa Mak Ka-KeiPrincess/Kiki | Princess/Kiki |
 Takeshi KaneshiroKenji / Mark Kim | Kenji / Mark Kim |
 Dennis Chan Kwok-SanPoliceman | Policeman |
 Kent Cheng Jak-SiPrincipal | Principal |
 Kingdom Yuen King-TanMs. Yuen | Ms. Yuen |
 Lau Siu-MingMr. Lau | Mr. Lau |
 Elaine Law Suet-LingFatty | Fatty |
 Bobby Yip Kin-SangNot listed | Not listed |
 Lui TatNot listed | Not listed |