In a Danish take on "Rain Man," director Soren Kragh-Jacobsen's "Mifune" observes a yuppie learning what's really important in life from his developmentally disabled older brother. After Kresten (Anders W. Berthelsen) marries the wealthy daughter of his boss, he's summoned home to face the impoverished rural past he never told her about. His father has died, leaving the forever childlike Rud (Jesper Asholt) in the decrepit farmhouse where they grew up. Kresten can still frighten and delight Rud by pretending to be actor Toshiro Mifune as a fearsome samurai.
   The savvy, sensitive Liva (Iben Hjejle) is hired to care for Rud. When her adolescent brother (Emil Tarding) also moves in, the four start to become a family but the outside world, including Kresten's wife, intrudes. Thanks to fine ensemble acting, the Dogma '95 aesthetic of hand-held cameras, available lighting and genuine locations works smoothly. There are few false notes, just many that resonate.    Starring Anders W. Berthelsen, Iben Hjejle, Jesper Asholt, Emil Tarding, Sophie Grabol and Anders Hove. Directed by Soren Kragh-Jacobsen. Written by Soren Kragh-Jacobsen and Anders Thomas Jensen. Produced by Birgitte Hald. A Sony Pictures Classics release. Black comedy-drama. Not yet rated. Running time: 103 min. Opens 2/25/00.