He earned his Doctor of Science degree with a thesis titled "The species of Anaptychia, with a new sub generic classification".
His research encompassed various lichen genera in Japan, including Anzia, Cetraria, Parmelia, Peltigera, Pilophorus, and Xanthoparmelia.
[1] Kurokawa played a crucial role in elevating the herbarium of the National Museum of Nature and Science (TNS) to international standards.
[4] His research extended to environmental studies, where he investigated the use of Parmotrema tinctorum as a bioindicator for air pollution in urban Japan.
[1] Kurokawa was widely respected for both his academic achievements and his personal qualities, including his warmth and kindness.