[3] There he directed PR films and documentary films, while also participating in the "Blue Group" (Ao no kai) with other Iwanami filmmakers such as Noriaki Tsuchimoto, Shinsuke Ogawa, and Yōichi Higashi, a group that was exploring new paths in documentary.

Kuroki left Iwanami after experiencing conflicts with the sponsors of his Hokkaido, My Love (1960), and it was his Record of a Marathon Runner (1964) that helped spark changes in the Japanese documentary world.

[4] Kuroki switched to fiction film, independently producing Silence Has No Wings (1966) and showing it at the Art Theatre Guild.

He became one of the representative figures of ATG and independent Japanese cinema,[2] and was particularly known for a series of works dealing with the atomic bombings of Japan, such as Tomorrow (1988) and The Face of Jizo (2004).

[5] Kuroki's work also dealt with his own feelings of guilt from the war, as he felt responsible when some of his fellow students, who had been conscripted to work in a local factory, died in Allied bombings and he did not help.