Yael Okuzaki, a professional assassin, crafts personalized gravestones for each target as a chilling prelude to their demise—a signature marking their inevitable fate. He operates under an unwavering code of professionalism, executing contracts devoid of personal bias and guarding client identities with absolute discretion. Concealed beneath an eyepatch lies a bionic eye interfaced with East Doroa’s surveillance grid, enabling him to monitor targets through hidden cameras embedded in statues and gargoyles, granting unmatched precision for his sniper craft.

A master of tailored weaponry, he designs tools like a robotic exoskeleton and a modified Maserati Bora outfitted with a hood-mounted Gatling gun and bulletproof glass. His obsessive attention to image manifests in an unvarying wardrobe of white Prada suits, swiftly replaced if marred. Before each kill, he ritualistically rolls a six-sided die to dictate the bullet count—a calculated flourish underscoring his lethal confidence.

Tasked by the East Doroan government, he assassinated Queen Malta, a peace-advocating singer, during her performance, aiming to destabilize East-West Doroa relations. Though initially failing to eliminate her bodyguard, Jigen Daisuke, subsequent clashes with Jigen and Lupin III escalated into high-stakes chases and sniper duels, with Yael manipulating surveillance systems to outmaneuver them. In their final showdown, Jigen exploited discrepancies in bullet physics to redirect Yael’s fire, shattering his arm and ending his sharpshooting career.

Adapting to his disability, Yael later employs a robotic arm to resume assassinations, eliminating figures like Codfrey at pivotal moments. His surname, blending the Japanese characters for "inner part" and "cape," alludes to concealed depths beneath his polished facade. Ties to an underground network and orchestration of geopolitical strife—including framing West Doroa for Malta’s murder to provoke war—cement his role as a shadow architect of grand-scale conspiracies.