Kaite was originally working for Brilliant Dynamites Neon , to help him raid the Sandsteamer. However, when B.D.N. told Kaite he planned to send the sandsteamer over a cliff and kill all the passengers, Kaite was dismayed and begged him not to. This angered B.D.N., who beat him and stuck a gun against his face. Kaite was paralyzed with fear, and B.D.N. might have killed him if Vash didn't show up to save him. After this he helps Vash outmaneuver B.D.N. and his men to take back the sandsteamer.
He believes Vash is too gentle with people, telling Vash that he should shoot to kill, or he'd get himself killed. He also appeared geniunely concerned when Vash was shot.
In a flashback in the anime, his father's gravestone read "Richard Trevisick". Therefore, Kaite's last name is Trevisick.