Species–abundance distribution (SAD) is one of the most basic descriptions of an ecological community. Vigorous controversy surrounded SAD from the 1940s to 1960s, and has since persisted. Isao Motomura first published a notable paper in 1932 to describe findings on SAD, and to provide an empirical model; nevertheless, this work has often been overlooked or incorrectly cited, probably due to being published in Japanese. Here, we introduce the works of Motomura with an English translation of the paper, and the subsequent research history of SAD. We also introduce the work of Numata et al., another Japanese paper, which provided the biological explanation for Motomura’s model of SAD, although it was rarely cited by subsequent studies. We summarize that Motomura was the first to fit a statistical model to observed SAD, and that Numata et al. attempted to explain the observed SAD via underlying biological mechanisms.