[2] When he was five, Takeshi died abruptly at the age of 38, leaving his three children Reiko, Kaoru and Yachiyo to his wife Taka.

[6] Osanai described these limits as an "existing theatrical poison", for he aimed to extend the boundaries of kabuki as part of the shingeki movement.

[8] His first production with the Free Theater, John Gabriel Borkman, brought Western naturalist and modernist drama which would challenge social conventions.

He helped produce and appeared in Souls on the Road, a groundbreaking work in Japanese cinema, and raised such important film talents as Minoru Murata, Kiyohiko Ushihara, Daisuke Itō, Yasujirō Shimazu, and Denmei Suzuki.

[10] On December 25, 1928, Osanai collapsed at a Chinese restaurant in Nihonbashi during a thank-you party held after the performance of Fumiko Enchi's first play Banshun Sōya, and died shortly after returning home.