Allen Isurugi, a visionary robotics scientist, engineered cutting-edge AI-driven animal drones—innovations designed as companions and helpers. His creations began with Melissa (AMD00), the pioneering prototype, then expanded to Kasumi (AMD01), Oboro (AMD02), and Madara (AMD03). Corporate forces soon targeted his work, aiming to repurpose the technology for warfare, but he fiercely resisted their militarization agendas, sparking escalating tensions.

As head of the Isurugi ninja clan, he defied tradition by championing his daughter Rikka’s scientific ambitions over ancestral duties, directly opposing her grandfather Hyoei’s rigid adherence to legacy. When his former associate Lauren launched a violent assault, Allen triggered the drones to secure Rikka’s escape, deliberately drawing enemy focus to himself. His self-sacrifice became the catalyst for her emergence as a justice-driven vigilante.

A final message uncovered after his death expressed unwavering faith in Rikka’s future, paired with the legacy of a cyber-augmented "Black Fox" ninja suit—an emblem of his philosophy uniting technological progress with clan history. His pioneering studies on AI ethics and human-esper hybridization emerged as a linchpin in global power struggles, with adversaries vying to weaponize his breakthroughs while allies fought to preserve their humanitarian intent.