what's the title of this anime show?

I forgot the title of this anime that aired late nights either on hbo or encore or either cinemax,

its about a girl who is a teacher or an undercover teacher i think, who is actually a daughter of a mafia group, which she is treated and respected by the men as a princess.

but she can kick butt.

she helps her student if they get hurt by beating up the ones that stirr up trouble with them and so on