Wikipedia
Bichunmoo is a South Korean martial arts film written and directed by Kim Young-jun featuring Kim Hee-sun and Shin Hyun-joon. Originally released in 2000, it was at the time the most expensive film in Korean history (an honor it soon lost to Musa).
In 12th-century China, during Mongol rule, childhood sweethearts Jin-ha and Sullie are separated but vow to reunite. Orphan Jin-ha begins training in the Bichun martial arts and discovers his father was a swordsman murdered by the Mongol army. Meanwhile, Sullie's father, a Mongol general, arranges for her to marry a Mongol noble. Believing Jin-ha to be dead, Sullie marries the noble. Recovering from near-death, Jin-ha takes on the persona of bandit Jahalang, and begins an anti-Mongol crusade with the help of his army of warriors. Finally Jin-ha and Sullie are re-united, when Jin-ha's bandit warriors infiltrate Sullie's family manor.