Yamamoto Tatsurō (June 16, 1910 – January 24, 2001) was a Japanese historian of Oriental history. He served as a Professor Emeritus at the University of Tokyo and was a recipient of the Order of Culture. He is known as the person who proposed the Japanese era name "Heisei". His wife was Sumiko (壽美子), the second daughter of Kunizo Hara.
Source: “Yamamoto Tatsurō”, English Wikipedia (CC BY-SA 4.0), excerpt