In "Mother," 20-something Yoon Do-joon (Bin Won) lives with his mom (Hye-ja Kim), still sharing a bed with her and allowing her to treat him like a boy. She watches Do-joon while she works, worries about him when he isn't home, and has generally devoted her entire being to his well-being.

Unfortunately, Do-joon is kind of a blockhead. He can't remember what he's been doing from one day to the next, and he's prone to screwing up the simplest tasks.

So when hapless Do-joon is arrested for murdering a teenaged neighborhood girl named Moon Ah-jung (Mun-hee Nah), Mother goes into crisis mode. The police don't intend to investigate any further than Do-joon, and his lawyer's best suggestion is five years in a mental institution, so she takes it upon herself to investigate Moon's death.

As we follow her fact-finding mission around her South Korean town, we begin to see through her passive, affable exterior to a woman willing to do whatever it takes to prove her son's innocence. She first accuses his friend Jin-tae (Ku Jin), and when he's cleared, enlists him as a knuckle-breaker as she tries to squeeze information from local goons.

And that's only the beginning.

"Mother" is rare in that it can be incredibly visceral at times " it contains sex, murder, vomiting, amputation and a foot-induced toothectomy " and yet manages to retain a tonal lightness that keeps the subject matter from becoming too heavy.

The film screens Friday and Saturday at the Oklahoma City Museum of Art. "Mike Robertson