This article aims to clarify the historical background regarding why psychiatric occupational therapists pointed out the ambiguity of their professional roles in the 1990's after over 25 years of legislation on occupational therapists. Findings regarding their social background and interviews with the nurses and instructors who were engaged in occupational therapy before the legislation are as follows: (1) Actual conditions of the nurses and instructors were not fully reflected in the clauses. This seems to create a separation between old and new people in this field. (2) Although social prejudice against the patients and chronic shortages of manpower existed, the objectives of treating the patients as human beings and collaborating with them (not having them work) were regarded as being important. This seems to have been one of the "guidelines" of Doctor Shuzo Kure in the Meiji Era.