Ippen
Ippen was the founder in 1274 of the Jishû sect of Amida Buddhism, which advocated that since Amida is present everywhere, there is no need to construct new, separate, places of worship, but rather that one should sing and dance in praise of Amida everywhere, including in the Buddhist temples of other sects, and at Shinto shrines.
References
- Tsunoda Ryûsaku, Sources of Japanese Tradition, 1st Edition, vol. 1, Columbia University Press (1968), 188.