He wrote several books on the birds of Japan and worked on Japanese encephalitis, the systematics of shearwaters, ducks and on avian anatomy.
He worked briefly with the US Army 406th Medical General Laboratory, collaborating with Dr. Oliver L. Austin.
He then moved to the Yamashina Institute of Ornithology where he worked for the rest of his life.
[2] He also wrote on avian anatomy, including notes on the pectoral,[3] and cervical muscles.
[4] A fossil species of shearwater Calonectris kurodai was named in his honour.