Nihon Shūkyōsha Heiwa Kyōgikai
Nihon Shūkyōsha Heiwa Kyōgikai (日本宗教者平和協議会) was founded in 1962. This group is composed of “people with faith” from any religious group, including Buddhism, Christianity, Shinto, Tenrikyō, and new religions.
This organization has supported various anti-war and peace movements since 1962 and is against constitutional revision; they have called for total elimination of nuclear weapons, removal of the US bases from Okinawa, and cancelation of the US-Japan Security Treaty.
In 2015, they published a statement to criticize the Abe administration for its security bills. Their statements are available here.