The former studies of history of adult education regarded the movement for improvement of life in the Taisho era as the educational work aimed at new middle class in cities. On the other hand, the models of life this movement proposed were appropriate to the life of the upper part of new middle class. In the later Meiji era, the concept of “middle class" the advocates of improvement of living had used was ambiguous, and often was accompanied by the expectation of “the core of society". The idea of “the core of society" was related to the proposition of “simple life", which was recommended to the “middle class" in order to avoid luxurious and corrupt life, and to keep their lives sound. These ideas influenced the movement for improvement of life even in the Taisho era.