After her daughter is brutally assaulted and raped by a group of racist boys at school, a tough Vietnamese beautician seeks to torture the boys’ mothers at her beauty salon.

Just add a motive for the torture and then tighten your wording.

"To avenge her daughter's rape by a racist classmate a Vietnamese woman abducts and tortures the boys mother."

To avenge may be wrong. But rape always comes with the knowledge of brutality so you don't have to say that, words you get for free.

Hope it helps.

"When the spoiled rich boy who raped her daughter is freed, an angry Vietnamese woman kidnaps the boys powerful mother who bribed the judge."

Since the protagonist is the character inflicting the torture, do you want ?the audience to at least initially sympathize with her -- or you don't care?

?If you want to elicit the audience's sympathy for the woman then the logline should indicate that she resorts to torturing the mothers ?after the justice system fails to punish the kids. ?The kids ?get off because of the parents prominence in the community.

?But then?why would the women continue to patronize the business of the woman whose daughter accused their darling sons of rape?