[Review of the time "Kaishun Byoshitsu" was founded: is the date "1899" correct?].

It has been an accepted story until today that in 1899 Kensuke Mitsuda's efforts led to the founding of "Kaishun Byoshitsu", an isolation ward for leprosy patients in Japanese modern times first located in the Tokyo City Yoikuin (poorhouse). But, in this paper, the author has collected as many documents that describe the details of the foundation of "Kaishun Byoshitsu" as possible, and thoroughly further reexamined definite sources regarding the time when it was founded. The documents are classified into the following four by the author, [A]: Kensuke Mitsuda himself, [B]: the persons concerned with Mitsuda, [C]: the persons involved in Yoikuin, and [D]: general researchers. These classifications [A] to [D], are further divided into two insistences, according to whether the founding date was claimed to be in 1899 or in 1901 in [D]. Insistences are exhibited in [B] for "in 1899" and in [C] for "in 1901", respectively. However, there was no conclusive "definite source" clearly specified in the above-mentioned classifications [A] to [D]. Additionally, in the most reliable classification [A], there is no actual reference to the founding date. Therefore, the author has reached the conclusion that at least the claim that the founding date was 1899, though it has become an accepted story, is not based on any solid evidence.