In 1331, during the era of the eighth Zenna Kuen, a plague raged through Kyoto and he performed the ritual of the seven-day nenbutsu Hyakumanben (literally, "a million times") by the order of Emperor Godaigo and ended the plague; consequently, the temple was given the title 'Hyakumanben.'
1331年（元弘元年）第8世善阿空円のとき、京都に疫病が蔓延し、後醍醐天皇の勅により七日念仏百万遍を行い疫病を治めたことから「百万遍」の号が下賜された。