Jacob is Director of E=X, the organization managing Eden's security. He recruits hacker Eiji Takanaka for his exceptional abilities in the "Hard On" virtual reality game, recognizing Eiji's potential to pilot the transformable Garland units against netjackers. As Eiji's superior, Jacob assigns missions targeting the netjacker resistance.

His controversial actions escalate when he seizes control of Eiji's mind during an operation, attempting to force him to kill netjacker leader Sion. This violation directly triggers Eiji's defection from E=X to the netjackers. Jacob subsequently emerges as a primary antagonist, demonstrating absolute loyalty to Eden's governing "System."

Later, Jacob clashes with Eden's spiritual leader, Bishop Won Dai, over control of the System, opposing Won Dai's Project Heaven as contradictory to System directives. This conflict culminates with Jacob piloting a Garland unit against both Eiji and Won Dai's forces. His commitment drives him to pursue Eiji into Eden's lower levels, leading to a final combat where Jacob is defeated. Jacob's background prior to E=X remains undocumented; his development centers solely on his transformation from authority figure to antagonist through escalating enforcement of the System's authority.