Anzai was a woodsman who lived near Sukoshi Zutsu. His family had been ashigaru warriors for centuries, and so was he, until Anzai lost his leg in Otosan Uchi. In 1166 Anzai found Ikoma Korin and Matsu Kenji in the forest after a battle near the village in the War of the Rich Frog. He offered then refuge when he saw how badly they were wounded.