On August 11, 1507, when Masamoto, who often behaved peculiarly and was obsessed with Shugendo (Japanese mountain asceticism-shamanism that incorporated Shinto and Buddhist concepts) went into the bathhouse on his premises in preparation for acquiring magic, he was assassinated by the uchishu members Nagatada YAKUSHIJI and Motonaga KOZAI, who supported Sumiyuki.
永正4年（1507年）6月23日、修験道にとりつかれ、度々奇行のあった細川政元は、魔法を修する準備として邸内の湯屋に入ったところ、澄之を擁する内衆の薬師寺長忠・香西元長らに殺害された。