After World War II, Irino, along with colleagues Minao Shibata and Kunio Toda, studied the twelve-tone method of composition devised by Arnold Schoenberg.

[1] During the same time, the magazine Ongaku Geijutsu published two articles by Irino: "Schoenberg's Composing Technique" and "What is Twelve-Tone Music?".

Subsequently, Irino used the twelve-tone technique in numerous compositions and wrote extensively about contemporary music.

Working to introduce foreign contemporary music and music literature to Japan, he made Japanese translations of important books such as Die Komposition mit zwölf Tönen (12音による作曲技法) by Josef Rufer and Schoenberg and His School (シェーンベルクとその楽派) by René Leibowitz.

Irino did not, however, compose serial music, a technique of the same period widely used with the Darmstadt School.