Kengo served as a monk of the Jōdō Shinshū, or True Pure Land School, of Buddhism during the Sengoku period. Kengo served as the second abbot of the Gantoku Temple in Kawachi Province.
Kengo was born as the eldest son (and second child) of Jitsugo, the first abbot of the Gantoku Temple. Jitsugo was the son of Rennyo, the eighth high priest of the Hongan Temple. Similar to his father, Kengo’s common name was Chūjō. Kengo’s older sister was married to Umehara Genin. His younger brother, a Zen monk, was named Juhō. Kengo was said to have been adopted by Saionji Sanenobu, but, based on the birth years, this appears incorrect. His wife, Ryōmyō-ni, was the daughter of Shiba Yoshimune.
In 1558, Kengo entered the priesthood under the tutelage of Kennyo, the high priest of the Hongan Temple. Later, he inherited his father’s position as the abbot of the Gantoku Temple. At the Battle of Ishiyama which began in 1570, Kengo followed the lead of Kennyo by holing-up in the Ishiyama-Hongan Temple and fighting against Oda Nobunaga.
In 1589, an incident occurred whereby the perpetrators left graffiti on the white walls of the guardhouse at the palace of Toyotomi Hideyoshi in Kyōto. The graffiti referred to Hideyoshi and the state of society. Maeda Geni discreetly cleaned-up the graffiti, but after Hideyoshi learned of the incident, he punished seventeen of the guardhouse staff with crucifixion.
The Tenma-Hongan Temple allowed a number of rōnin, or wandering samurai, who had incurred the wrath of Hideyoshi to hide on their premises. As a result, the Hongan Temple was subject to an investigation by Hideyoshi and, in particular, Kengo and his wife were detained. Kengo was identified as the person responsible for concealing the rōnin, surmised to be because included among the rōnin were members of the Shiba clan which was the original family of his wife. Thereafter, Bitō Dōkyū and the rōnin hiding in the Hongan Temple were sent to Kyōto be crucified while, on the evening before their departure, Kengo took his own life. After his death, Kennyo conferred a specially embroidered platform upon the Gantoku Temple out of recognition for Kengo’s contributions. After his head was displayed in public, his remains were returned to the Gantoku Temple where he was interred.