Buddhism is alive and well in Japan. Having said that the lines between Buddhism and Shinto are significantly blurred. In addition 70% of Japanese profess no religious affiliation at all.
Be that as it may Buddhism came to Japan in the 6th Century so its roots are deep. Like so many religions Buddhism was not immune to splits and Chion-in Temple fits into this mix as it is the
“headquarters of the Jōdo-shū (Pure Land Sect) founded by Hōnen (1133–1212), who proclaimed that sentient beings are reborn in Amida Buddha’s Western Paradise (Pure Land) by reciting the nembutsu, Amida Buddha’s name. The vast compounds of Chion-in include the site where Hōnen settled to disseminate his teachings and the site where he died.” – Wikipeida

AloJapan.com