Emperor Seiwa

Emperor Seiwa (清和天皇, Seiwa-tennō; May 10, 850 – January 7, 881) was the 56th emperor of Japan, according to the traditional order of succession. Seiwa's reign spanned the years from 858 through 876. He was the ancestor of the Seiwa Genji, who later became the leaders of the warrior class.

Before his ascension to the Chrysanthemum Throne, his personal name (his imina) was Korehito (惟仁), the first member of the Imperial house to be personally named "-hito" 仁. One meaning of the character 仁 is the Confucian concept of ren. Later it has been a tradition to name the personal name of all male members of the Imperial family this way. He was also known as emperor as Mizunoo-no-mikado or Minoo-tei.

Source: Wikipedia — https://en.wikipedia.org/wiki/Emperor_Seiwa