Iwanami entered Tokyo Imperial University in 1905, where he became interested in the teachings of Uchimura Kanzō, although he never converted to Christianity.

Also, during this period, he established a literary circle with his close friend, Yoshishige Abe and held weekly meetings in his home with leading authors to discuss intellectual matters.

Even after Natsume Sōseki died in 1916, ongoing revenues from the publication of his works provided Iwanami with the funding necessary to proceed with numerous projects.

[1] From late 1927 to early 1928, he toured Manchuria and north China as a guest of the South Manchurian Railway, together with Kiyoshi Miki .

[3] However, he drew the wrath of Japanese militarists by publicly denouncing the Second Sino-Japanese War as “a war Japan should not be involved in,” and in 1940 he drew unfavorable attention again by publishing works by Tsuda Sōkichi that questioned the veracity of Japan’s historical antecedents as described in the Kojiki and Nihon Shoki.