Caswell was the class chairman of Yuma Tsukumo's class. He was able to figure out why the school's computer system went down, saying that someone tampered with the city's main computer. He Dueled Yuma that day, as they could not access their online books in Mr. Kay's class. Caswell soundly defeated Yuma without taking a single point of damage, as Yuma could not access his Extra Deck since Astral was not present.