Japanese companies often criticize themselves on their own “nurumayu [lukewarm] nature”; however, in reality, according to Takahashi (1989), the lukewarm feeling felt by organization members can be explained through the effective temperature hypothesis. An organization's propensity to change as a system is measured as system temperature, while a member's propensity to change as an organization person is measured as body temperature. The lukewarm feeling felt by members can then be explained using effective temperature, which is defined as the system temperature minus the body temperature. This paper validates the effective temperature hypothesis using data from Survey X, an exhaustive survey of all employees of Japanese Company X, which is successful in organizational reform. The survey was carried out once a fiscal year, during the fiscal years 2004–2013. Like the results of the JPC Survey of Takahashi (2013), those of Survey X show the coefficient of determination of 0.9840 with a surprisingly neat straight line, demonstrating a direct relationship wherein the lukewarm feeling ratio drops as the effective temperature rises.