Eijitsu (1201 – January 21, 1215) was the third son of MINAMOTO no Yoriie, the second seii taishogun (literally, "great general who subdues the barbarians") of the Kamakura bakufu (Japanese feudal government headed by a shogun). Seiwa Genji (Minamoto clan). His mother was a daughter of Soi (rank of Buddhist priest), Shokan IPPONBO. A paternal half-brother of MINAMOTO no Ichiman, Kugyo and Take no Gosho, and an older brother of Zengyo. His childhood name was Senjumaru.
When his father Yoriie died, he was only four years old. After his father's death he was brought up by Nakatsukasajo OWARI, but backed up as a Daishogun (command-in-chief) by Chikahira IZUMI, Gozoku (local ruling family) of the Shinano Province (the present Nagano Prefecture) who had antipathy toward the Hojo clan, and forced a conspiracy to assassinate Yoshitoki HOJO, when the conspiracy was exposed in March, 1213, he was arrested by the Hojo clan (Chikahira IZUMI War). In December 1213, following the order of his grandmother Masako HOJO, he became a priest and a disciple of Eisai, and named his homyo (a name given to a person who enters the Buddhist priesthood) Eijitsu. In 1214, backed up by the remnants (of a defeated party) of the Wada clan when he stayed in Kyoto, he tried to attack the Rokuhara government, however, the plot was discovered by the bakufu side and on January 21, 1215, when he was attacked by them in an inn around north of Ichijo, he committed suicide. It is said that he died at the age of 14.