It's wonderful to see a Japanese movie in which a samurai, for all his somber discipline and skill, is also a touching and complicated ordinary man. Seibei (Hiroyuki Sanada), the central figure in The Twilight Samurai, is an expert 19th-century warrior who lacks even a hint of bravado. Quiet and unkempt, with a wisp of beard that brings out the sadness in his eyes, he occupies the lowest rung of his clan and supports two daughters and a senile mother by working as a warehouse clerk. At times, he recalls no one so much as Dustin Hoffman in ''Kramer vs. Kramer,'' yet when Seibei finally does unsheathe his sword, I can't remember an action sequence that holds you in quite the same way, drawing deep excitement out of its hero's fearless desire to live more than fight.

