Tokugawa Ieyasu had many concubines, and Oman-no-kata was a particularly beloved consort in his later years. Around the time of the Osaka Campaigns (1615), Oman retired from service and settled in a hermitage at Okazu; when news of Ieyasu's grave illness at Sunpu reached her in 1616, she hurried to his deathbed, where he gave her an Amida Nyorai image by Ankyo (traditionally attributed to Kaikei). After his death, Oman founded this temple in Totsuka to enshrine the image — the origin of Seigen-in. During the Edo period, daimyo processions passing the temple gate would lower their spears horizontally as a mark of respect to its Tokugawa ties. A cultural-historical site along the Tokaido Totsuka-juku preserving Ieyasu's religious faith and his connections to the women of his life.