Movie
Description
Kouzou Fuyutsuki is the Deputy Commander of Nerv, functioning as the organization's second-in-command and the most trusted subordinate of Commander Gendo Ikari. His background is rooted in academia rather than the military. Before Second Impact, he was a professor of metaphysical biology at Kyoto University. During that period, he met a brilliant bioengineering student named Yui Ikari and became her mentor and academic advisor. Over time, he developed a deep but unspoken fondness for her, always maintaining a professional distance even as their working relationship grew close. Through Yui, he was introduced to an enigmatic man named Gendo Rokubungi, whom he initially found distasteful and later bailed out of police custody at Yui's request. When Yui revealed her romantic relationship with Gendo, Fuyutsuki was visibly unsettled, though he concealed his true feelings.

After the cataclysm of Second Impact, Fuyutsuki's university career ended. He worked briefly as an unlicensed physician in the ruins of Toyohashi before being anonymously recommended for a United Nations investigatory expedition to the South Pole. During this mission, he became determined to uncover the truth behind Second Impact and the shadowy organization Seele, which he now realized was connected to Gendo and Yui. Through independent research, he pieced together a web of deception and eventually confronted Gendo at the Artificial Evolution Laboratory. Gendo, unfazed, led him into the Geofront and revealed the construction of a prototype Evangelion unit, then invited him to "join us in creating a new genesis for Mankind." Fuyutsuki accepted, though the choice was effectively coerced, as Seele had threatened to make him disappear for knowing too much. He later confided to Yui that working for the enemy was his only means of survival.

As Deputy Commander, Fuyutsuki manages the routine operations of Nerv whenever Gendo is absent, handling matters such as town council meetings, paperwork, and command during crises. He is not a military officer, yet he carries himself with a composed, professional bearing that allows him to take charge when needed. His role in the story is that of a steady, observant lieutenant who occasionally provides critical commentary on events and quietly navigates the dangerous currents between Nerv, Seele, and Gendo's private agenda. He is frequently at Gendo's side on the bridge, offering remarks that illuminate the setting's background and the stakes at hand. When pilot performance causes excessive collateral damage, he does not hesitate to chastise the Eva pilots directly, reminding them that their duty is to defeat the Angels, not to make grotesque displays.

Fuyutsuki's personality is defined by a reserved, scholarly disposition. A former colleague once noted that while he excels at his work, he does not take socializing seriously. He remains a lifelong bachelor with no known dependents. Beneath his detached exterior is a genuine concern for the people under his command. At the same time, he is pragmatic enough to recognize that Gendo's ruthlessness is sometimes necessary given the hidden threats from Seele. He functions as an external conscience for Gendo, someone who questions him and occasionally expresses a more humanistic perspective. In one philosophical exchange, Fuyutsuki states his preference for a world where people live, no matter how stained with sin, aligning himself more with Yui's ideals than with Seele's plans.

His primary motivation stems from a desire to see Yui Ikari again, the thread that binds him to Gendo's scheme even as he dislikes the man. He is aware of Gendo's ultimate goal of reuniting with Yui through Instrumentality, and this shared longing creates a strange unity between the two men. Fuyutsuki possesses no supernatural or combat abilities; his strengths lie in his sharp analytical mind, extensive scientific knowledge, and years of academic expertise. He also has some medical training, having acted as a physician in the post-Impact chaos. As the series progresses, he remains a constant, increasingly weary observer of the accelerating events, and his final moments in Instrumentality show him being comforted by an apparition of Yui, confirming the depth of his lifelong affection.