[2][3] His main contribution include the first observation of alpha particles using nuclear emulsion photography.

He left Japan and first worked as an intern under Woldemar Voigt at the University of Göttingen.

His groundbreaking research on alpha particles, based on the work done at Manchester, was first presented at the meeting of the British Science Association in Winnipeg[7] in 1909, and was published shortly afterward in 1910.

[4] Upon returning to Japan, he taught physics at the Tokyo Imperial University from 1914 to 1933.

[8] Kinoshita was awarded the Imperial Prize of the Japan Academy in 1923 for his work on radioactive particles.