TV-Series
Description
Zack Walker is a 17-year-old male standing 1.85 meters tall and weighing 76 kilograms, with slightly tan skin, short white spiky hair, and blue eyes behind frameless glasses. His birthday is June 9.

Raised by Jed Walker, a cold and emotionally distant bio-technology researcher, Zack learned early he was viewed primarily as a vessel for future consciousness transfer. A childhood attempt to connect—drawing a picture for his father—ended with Jed discarding it immediately, reinforcing Zack's perception of being an object. Despite this neglect, Zack developed exceptional intellectual abilities, possessing an IQ of 200. He deliberately pursued scientific fields distinct from his father's work, eventually earning a spaceship pilot's license.

As the primary pilot and mechanic for the spacecraft Astra during a stranded deep-space mission, Zack's technical skills were vital. He calculated their position as 5,012 light-years from home and devised a planetary-hopping return route. He executed crash landings, repaired ship systems, conducted lab tests, created edibility testers for alien life, and engineered the merging of two damaged ships into one functional vessel.

Zack maintained a longstanding relationship with childhood friend Quitterie Raffaeli. They had emotionlessly agreed to marry as children, though Quitterie later dismissed it as play. During the journey, specifically on planet Icriss, Quitterie confessed her feelings. Zack revealed he had always loved her, leading to their engagement and eventual marriage.

Typically reserved in emotional expression, Zack nonetheless demonstrated care for others. He treated Funicia Raffaeli protectively, almost like a sister, assisting her with activities like making paper doll chains. He trusted Kanata Hoshijima deeply, consistently sharing critical discoveries with him first and promising to serve as Kanata's pilot for future space exploration.

Later, Zack learned from Charce Lacroix that he was a clone created by Jed Walker and Olive Raffaeli as part of a project developing spare bodies for consciousness transfer. This confirmed his childhood belief about Jed's view of him and revealed broader truths about their home planet's history and a murder plot against their group.

The journey fostered subtle emotional growth. While Zack rarely displayed emotions externally, he developed stronger bonds with his companions. He prioritized logic but demonstrated capacity for emotional connection through his engagement to Quitterie and protective relationships like that with Funicia. The revelations about his cloned nature and intended purpose did not alter his fundamental personality but provided context for Jed's treatment and his own choice to pursue a scientific path independent of his father's work. His technical expertise and analytical thinking remained essential to the group's survival and return.