Although the medical community had lost confidence in neurobiology, one individual worked against the tide: Kaneko Junji, who had championed biopsychiatry during the prewar period. His effort to once again reinvigorate the discipline was a brief but meaningful parenthesis in the history of medicine in postwar Japan. Kaneko engaged in a tireless crusade that aimed at strengthening the foundations of psychiatric institutions. Beginning in 1947 and culminating in 1949, he worked to establish the first psychiatric association, the Japanese Psychiatric Hospitals Association [Nihon Seishinbyōin Kyōkai], which initially included 82 private hospitals. Also with his indefatigable support, the Japanese Nurses Association [Zen’nihon Kangōnin Kyōkai], founded in 1947 and initially limited to the Tokyo area, grew to the point that it included the rest of the nation in 1949. Ultimately, Kaneko pushed for the passage of a new mental hygiene act that prohibited domestic confinement. Thanks to his efforts, the proposition reached the Ministry of Health and Welfare [Kōseishō], and the Mental Hygiene Act [Seishin Eisei Hō] passed in 1950, encouraging access to institutional medical care. 2 Kaneko not only supported institutional psychiatry, but was also convinced of the conceptual validity of neurobiology and biological mechanisms as the primary object of psychiatric investigation. As a result, he was reluctant to accept the environment as a significant influence on psychiatric conditions. However, Japan was not yet ready to embrace the rehabilitation of biopsychiatry.