As the Fujufuse (Not Receive and Not Give (from and to people other than those belonging to the Nichiren Sect)) School, a fundamentalist faction of the Nichiren Sect, was banned in 1665, people affiliated with the faction became targets of shumon aratame, which aimed at converting heretics to other Buddhist sects.
1665年（寛文5年）には日蓮宗のうち強硬派である不受不施派が禁制となったことにより、他宗派に改宗させる宗門改の対象となった。