(Cantonese: 點解阿Sir係阿Sir[a]), is a 2011 Hong Kong television drama starring Moses Chan, Linda Chung, Tavia Yeung, and Ron Ng produced by Lau Kar Ho.

Despite the fact that he comes from a long line of disciplined workers, Law Yiu-wah (Moses Chan) is a teacher at a notorious school.

Wah also finds himself in a contest of wits with Inspector Ching Man-lik (Ron Ng), who has been assigned to work as a liaison officer at the school.

All of a sudden, Wah, Suet, Lam, and Lik find themselves involved in a complicated love square.

in Episode 27, When Linda Chung < Miss Koo> crumble, Average Points 34 and Peaking Points 38 a ^ The original title "點解阿Sir係阿Sir" was actually written in Cantonese; the title of the drama could be translated in Mandarin as "為何阿Sir是阿Sir"