The film tells the story of the thousand-year-old fox Youbi who was attracted by the boy Kunyi and began to interact with humans out of curiosity, thus entering a new world full of adventure.

The graphics and coloring of "Millennium Fox" have inherited the clear characteristics of Korean movies. Although it may not be comparable to many Japanese and American animated movies, it is already a film of considerable standards. The film does not deliberately show off stunts, but is down-to-earth, using traditional two-dimensional animation and a moderate amount of computer special effects. The effect is natural, unified and precise, and it is very consistent with the story.

It is also commendable that the plot of the film develops naturally without forcing a happy ending, which makes the story more touching and better implements the film's animation style. In addition, the music is also well matched, and the beautiful melody can be said to add a lot to the story. In the film, there is not only the protagonist Millennium Fox, but also many unique characters. These characters enrich the entire film and make it more interesting.