A Matter of Customs (Chinese: 雷霆第一關; Cantonese: Lui Ting Dai Yat Kwan) is a TVB program in Hong Kong starring Liza Wang, Danny Lee, Wong Hei and Jessica Hsuan.

Moon (Jessica Hsuan) is transferred to Ming's (Liza Wang) division.

Ming suddenly finds herself falling for Shan (Danny Lee), a distinguished man in the publishing industry.

Wong Hei chases after her, and he comforts her telling that she is not responsible for her family that she cannot take care of his girlfriend.

Jessica frantically searches for him in vain even when they try to bring her up on the boat, but The series ended with many unanswered questions including if Kong die and what the numbers he gave Shan.

So TVB aired the MV of the series subtheme song "To Love Like the Sea" sung by Wong Hei.

The letter states: Moon, I heard that when you die, each person gets a second to review their whole life, but I got an extra second and that second totally belongs to you.

There are two versions of it, one is a far view of Wong Hei and Jessica side-by-side holding hands in the sea.