Dr. Seijiro Inui, the chairman of the Institute for Psychiatric Research, wields significant authority over dream-exploring technology. Paraplegic and using a wheelchair, his condition and position earn him the nickname "the Chairman." He initially presents as a principled opponent of the DC Mini, arguing it violates the sanctity of the dream world against the "inhumane horrors of reality and technology," leading him to formally ban the device after scientists suffer mental breakdowns. However, his protective stance masks darker ambitions. His true goal is to harness stolen DC Mini prototypes to manipulate dreams, aspiring to become an omnipotent being capable of rewriting reality. To achieve this, he recruits Dr. Morio Osanai as an accomplice, offering shared dream control in exchange for using Osanai's physical body for mobility. This partnership turns coercive as Inui disregards Osanai's pleas to spare Dr. Chiba and demands her elimination when Osanai hesitates. His actions inflict severe harm. Invading researchers' dreams, he induces mental breakdowns that leave victims like Kei Himuro emotionless shells. Another colleague, Dr. Torataro Shima, attempts suicide by jumping from a window due to mental destabilization caused by Inui's dream terrorism, narrowly surviving by landing in a tree. These events escalate as dreams and reality merge, culminating in a chaotic parade of nightmarish imagery overrunning Tokyo. During the climax, he manifests within the collapsing dream-reality as a colossal humanoid nightmare entity. In this form, he openly declares his megalomaniacal intent to dominate all existence and plunge the world into perpetual darkness. This transformation underscores his role as the architect of the catastrophe. His defeat occurs when Paprika, having integrated her identity with Dr. Chiba, merges with Dr. Tokita's dream form, generating an infant entity that consumes Inui's nightmare manifestation. The infant ages rapidly during the consumption, ultimately dissolving Inui and restoring order.