Kuroda began studying closely works by prominent Japanese philosophers, among them Katsumi Umemoto, Akihide Kakehashi and Kōzō Uno.
In 1956, following Soviet Premier Nikita Khrushchev's "Secret Speech" and the brutal suppression of the Hungarian Revolution, Kuroda developed a strongly Anti-Stalinist position and turned against the Japan Communist Party (JCP).
In 1959, Kuroda Kan'ichi was expelled from Kakukyōdō in the wake of a scandal in which he tried to sell compromising information about the JCP to the Tokyo Metropolitan Police Department (MPD).
[1] At Kuroda's urging, Kakukyōdō-affiliated students participated vigorously in the massive 1960 Anpo protests against the U.S.-Japan Security Treaty adopting a Trotskyist approach of taking "direct action" to "expose the inherent contradictions of Japanese monopoly capitalism.
Kuroda penned over fifty books, published both in Japan and other countries, on such subjects as Marxist philosophy, analysis of Soviet society, Japanese cultural history, theory and praxis of organization building, and contemporary politics.