Zack Walker (ザック・ウォーカー) is a member of Group B-5. Zack has slightly tan skin with short white spiky hair, and blue eyes covered with frame-less glasses. His crust suit, a Falken make, is mostly turquoise, navy blue, and neon green with pink outlines on it. In the manga, his suit is also the only one not to feature the Caird High School logo on the shoulders; at his request, the logo was placed on the chest instead, leaving the shoulders open for the Falken chevron logo. He is a very intelligent and serious student with an IQ of 200. He tends to prioritize logic above everything else and is good at analyzing things and knowing essential facts. While it appears he has trouble connecting with others emotionally.