Aside from his voluminous academic essays on numerous aspects of Japanese culture he has also composed theatrical works on figures as varied as Yamato Takeru and Gilgamesh.

His mother Chiyo Ishikawa died early while Umehara was being breast-fed, and his father was still a student at Tohoku University.

Over the following two years he developed a passionate interest in the philosophies of Nishida Kitarō and Tanabe Hajime, the intellectual leaders of what was known as the Kyoto School (Kyōto Gakuha), a circle of conservative modernists who gave substantial theoretical backing to Japan's imperial outreach during the period known as the 15-year war.

Umehara was also attracted by the philosophy of ethics being worked out by Nishida and Tanabe's former colleague, Watsuji Tetsurō, who had now shifted to Tokyo University.

By that time, both Nishida and Tanabe had retired, and Umehara's father, a practical man with a career in the Toyota company, initially opposed the idea of him studying philosophy.