Osanai Kaoru was a Japanese director, playwright, critic, teacher, theater manager, and translator. A key figure in the shingeki movement, Osanai is credited with moving the Japanese stage toward modernist Realism and Naturalism. The founder of several key shingeki companies, Osanai was heavily involved in actor training and the move toward a Stanislavskian-based realistic form of theater.

Osanai was born in Hiroshima in 1881. He graduated from Tokyo Imperial University in 1909 with a degree in English Literature. After graduation, he assisted Tanizaki Jun’ichirō in laughing and producing the literary journal Shinshicho [New Trends of Thought]; he also translated Western drama for the journal. In 1909 he formed the Jiyū Gekijō [Free Theater] with kabuki actor Ichikawa Sadanji II. Rejecting both kabuki and shimpa conventions, the Free Theater’s first production was Ibsen’s John Gabriel Borkman. From that point onward the Free Theater staged productions of modern realist plays, including works by Wedekind, Gorki, and Chekhov. Osanai and Ichikawa also made the decision to use professional kabuki actors in Free Theater productions; this did, however, result in a confusion of acting and performance styles, especially as Osanai pushed for an end to declamatory forms of kabuki performance in favor of more naturalistic modes of speech and action.