This paper illustrates the early period of electroacoustic music in Japan through an intensive examination of the source materials for historiography and analytical study, trying to illuminate the reception of Western techniques by Japanese composers, examining the rudiments of their original creative ideas. An extensive list of Japanese works with information about their accessible manuscripts, literature and available recordings is provided. All quotations from the articles or interviews in Japanese have also been translated into English by the author of this paper, unless otherwise stated. The graphic transcriptions presented in this paper have been produced by the author employing computerised spectrum analysis. The aim of this paper is to provide resources for further investigation into this topic, particularly for concerned researchers in other language regions than Japanese.