Si-yeon (Kim Tae-hee)
One of the best warriors among the old fox tribe. Si-yeon falls in love with a man, which is considered as a taboo in her tribe. She is tragically destined to choose either her tribe's prosperity or her love relationship with a man. She works as a museum curator in the man's world.

Moo-young (Cheon-jin)
Moo-young is the most competent warrior, also the expected-to-be chief of the old fox tribe. He is a stereotypical leader, having outstanding abilities to control his associates, and excellent combat capacities. He is intelligent and prudent, and seldom exposes what he thinks and how he feels. Moo-young feels desperate while Si-yeon whom he loves, is falling in love with a man, Min-woo.

Min-woo (Cho Hyun-jae)
Min-woo is a special agent trained to exterminate the old fox tribe, but falls in love with Si-yeon, an old fox warrior. As he loves Si-yeon, he becomes friendly to the old fox tribe. However, he again looks on the tribe as an enemy, after his associates including his younger sister are killed by them. He is a friendly and warm-hearted man, having a closely-tied relationship with people around him.

Chae-I (Han Yae-sul)
A female old fox hunter. She is the only one who possesses the ability to transform. With the attractive physical appearance, she is admired by numerous men but only loves Moo-young. However, there is one more obstacle to realize love with Moo-young aside from Si-yeon; Moo-young is a son of a family that exterminates her family.