She is one of John Smith's love interests, being the second one after Julie. She becomes a Plumber, and befriends and "tames" Yenaldoshi, who is always with her after his first appearance.
- Wolf Bane
- Wes Out
- War of the Worlds Part 1 (John Smith 10)
- War of the Worlds Part 2 (John Smith 10)
- Above and Beyond (John Smith 10)
- The Ultimate Enemy Part 1 (John Smith 10)
- The Ultimate Enemy Part 2 (John Smith 10)
- The Ultimate Enemy Part 3 (John Smith 10)
- War (John Smith 10)
- The Frogs of War Part 1 (John Smith 10)
- The Frogs of War Part 2 (John Smith 10)
- Vreedlemania (John Smith 10)
- Hades' Blessing
- Showdown Part 1 (John Smith 10)
- Showdown Part 2 (John Smith 10) (cameo)
- Mad World
- Revenge of the Vampire
- Final Siege
- Only Human (John Smith 10) (cameo)
Dimension 777 (John Smith 10: Final Fantasy)
Kai is one of the main characters of Final Fantasy. She is a member of the Hunters of Artemis, despising all men due to a horrible incident with one. She is over 200 years old. She is assigned to assist John in capturing his freed Omnitrix aliens, but she talks to no men at the beginning. Over time, as she gains trust in John, she speaks with him, and willingly follows him into battle. She possesses several chocobo that the characters ride.
Eunice, a Hunter who was kicked out, joins the Shadows and kills the Hunters. Kai goes on a revenge path, killing her in a climatic battle. She vowed to restore the Hunters after that. She possesses a magic bow that materializes when she needs it. She is a master archer.
Dimension 3 (Jane Smith 10)
Kai makes her appearance working at her Grandfather's museum. Jane and Ben go there for a "date," as Ben and Kai spark an interest in each other. Ben constantly flirts with her, which irritates Jane to no end. The two agree to see each other more often, devastating Jane.
In Dimension 30, Kai wears only a brown cover for her chest and a short skirt, wielding a spear. She takes the role of Looney Tunes' Lola Bunny, being quite eccentric and unstable compared to most of the other characters.