Jo is too smart and too audacious for ancient China. Held back by a society where girls are forbidden to go to school and expected to accept arranged marriages, she talks her father into letting her dress up as a boy to get an education. At school she meets Leon, a classmate who soon becomes her soulmate. When Leon learns Jo's true identity, he is overjoyed. Unfortunately, her parents have other plans for her -- plans that include betrothal to an ugly, wart-nosed man. As the wedding day approaches, Leon is devastated, but bold Jo determines to marry him -- no matter what new form their love may have to take. This animated retelling of an ancient Chinese legend, which prefigures Romeo and Juliet, beautifully expresses the theme of everlasting love, proving once again the old adage that butterflies are free.