Isshin-in Temple (一心院)
Isshin-in Temple is a Jodoshu sect (the Pure Land sect) temple at Higashiyama Ward in Kyoto City as well as the head temple of the Shasei school of the Jodo sect. Its sango (literally, "mountain name," the title prefixed to the name of a Buddhist temple) is Gunsenzan. Its honzon (principal image of Buddha) is Amida Nyorai (Amitabha Tathagata). Although the temple is surrounded by the premises of Chion-in Temple, Isshin-in Temple is independent and distinct from Chion-in.
When visitors climb the stone steps from the side of Miei-do Hall of Chion-in, at the left-hand side is the entrance to the Honen-byo Grave, at the face is the entrance to the general graveyard of Chion-in and at the right-hand side is the Sanmon gate (temple gate) of Isshin-in; the Hondo (main hall) of Isshin-in is located at the upper tier of Daibonsho (a large Buddhist temple bell). It is generally permissible to enter the premises of Isshin-in other than the hondo, which is all graveyard. Because this temple is part of the premises of Chion-in, sightseers to Chion-in often mistakenly step into the precincts of Isshin-in Temple, thinking it's a sightseeing spot.
This temple was founded in 1548 by Enyo Shonen (1513 - 1554), who was born in Edo, Musashi Province, and studied at Edo Zojo-ji Temple when he was given the premises of the temple by Kyoto Shorenin no miya. Shonen founded a new school called Isshin-in school, which is now the Shasei school of the Jodo sect. Though the school had more than 100 branch temples in the Genroku years (1688 - 1704), Isshin-in came under the control of Chion-in as a result of conflicts within the school. Because the tombs of the head priests of Chion-in who were miya-monzeki (in this case, heads who are imperial princes) were constructed at the highest tier of the graveyard through the Edo period, the graveyard area continues to be administered by the Imperial Household Agency.
A night in November to December of 1838, priestly Imperial Prince Soncho, who was then the head priest of Chion-in, had a dream in which a bevy of swans flew to the small mountain at the back of Isshin-in; he believed it was a good omen, and thus gave Isshin-in Temple the sango 'Gunsenzan,' since it had no other. At this time, the priestly Imperial Prince took up an ink brush and wrote the name 'Gunsenzan' in Chinese characters; he had disciples make the letters in the frame and had them hung at the Sanmon gate.