The history of Atami Imamiya Shrine is long, with the shrine being rebuilt in Shoji 2 (1200) by the order of Minamoto no Yoritomo. It is said that Minamoto no Yoritomo, during his exile in Izu, fled into the Izu mountains to escape pursuers and, once exhausted, discovered a spring nearby. After drinking from it, he regained his strength (Yoritomo's cup of water). Then, he revived, saw a large camphor tree and the shrine, and prayed for success and good fortune. Annually, on October 19, the evening festival is held, and the following day on October 20, the Imamiya Shrine Grand Festival takes place.