Zenshin (1151 - the year of death unknown) was a monk of Tendai sect in the end of Heian period. He was from Kajuji line of the Northern House of the Fujiwara clan and his father was FUJIWARA no Chikataka, a Sangi (councillor). His mother was a daughter of TAIRA no Tokinobu.
He became an adopted child of TAIRA no Tokiko who was an older sister of his mother, and established his position under Taira clan government. In 1178 he became Gon no Shosozu (a provisional junior rank in the second highest managerial position). He was called "Nii no Hogen" because his rank of Tokiko was Junii (Junior Second Rank).
In 1183, he left the capital to Saikai together with the Taira family, and at the Battle of Dan no ura in 1185 he was held captive with TAIRA no Tokitada who was his uncle and others. After being investigated he was exiled to Aki Province and lived there until he was remitted in 1189. It has been known that after the remission he returned to Kyoto and visited TAIRA no Tokuko who had led a secluded life in Ohara to make a waka poem saying, 'Today we survived and meet here again, while I miss the person who parted from this world." After that he was never heard of again.
He was also known as a waka poet and his poems were contained in "Gyokuyo Wakasyu" (Jeweled Leaves Collection).