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, to which he was preferential.
Zack 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, later it is discovered he actually can be emotionally touched in certain situations, though he rarely shows it externally.
in 2063 A.D., Zack gathers at Mousanish Spaceport along with the other members of Group B-5 except for Aries Spring and Kanata Hoshijima, the former who joins them shortly afterward and introduces herself. The teacher then introduces Quitterie Raffaelli and her younger sister Funicia Raffaelli who will be joining them as part of a unique task to take care of and teach a younger child. Once Kanata has finally arrived, the group then boards a spaceship to begin their four-hour journey to Planet McPa. Once they are able to move freely around on the cabin, Zack asks if there is a shower on the ship. Upon landing, they exit the spaceship and walk around for a bit when Luca Esposito points out a strange globe that's been approaching them. They try to run away from it, but the strange globe is able to absorb and send them all into outer space.
They are able to find a nearby spaceship and upon collecting their luggage, are able to board it safely. When Kanata asks if everyone is here and if they're hurt, Zack says that there is one person missing. Ulgar Zweig looks outside and sees that Aries is still floating outside, with her thrusters and communications unable to work. Kanata volunteers to go out and rescue Aries while the rest of the group watch over the cord tying him to the ship. He is able to successfully grab Aries and bring her back to the ship where she thanks him repeatedly. As the group wonders how they can get out of their situation, Zack is working on the ship's coordinates and finds some disturbing information. He says that they are no longer above Plane McPa and that they are 5,012 light-years away from their original location. The group could do nothing but react with shock at this news.
Spaceship Pilot/Mechanic/Lab Technician- Zack has a pilot's license and acts as the Astra's pilot. He flies the ship without incident for most of the journey, with their encounter on Icriss being the only exception. He is also capable of using the equipment in the ship's lab to perform tests on various things and is the creator of the edibility testers that the crew uses throughout their journey. He also acts as the ship's mechanic, repairing broken parts and overseeing the reintegration of the two damaged ships on Icriss.
Jed Walker Edit
Jed kept himself emotionally separated from his son. Zack made efforts to connect with him as a child but concluded that his work had deadened him psychologically, a belief that led him to choose a scientific occupation separate from his father's.
Quitterie Raffaeli Edit
He has loved her since they were children, but his lack of externally evident emotion led her to mistake his treatment of her for indifference. When she bares her emotions to him on Icriss, he reciprocates her feelings unquestionably, and they are engaged and later married.