Chiburijima Island was once a place of exile, often housing political criminals of high status. The fact that Chiburijima is so culturally diverse despite being a remote island is likely because the exiled brought their own cultures with them.
Among the exiled was a monk by the name of Sokuryō. At Ikkū Shrine, he was the director of the village playhouse and brought with him the the Mahaprajnaparamitra (Daihannya Haramittra-kyō) sutra enshrined there.
Here and elsewhere in Chiburijima, you will find many five-story pagodas that resemble garden lanterns of stone. These are thought to be graves of the renowned members of the exiled—the bigger the pagoda, the more renowned the person. Though they used to be scattered throughout the island, today they are concentrated around Ikkū Shrine.