However, it is a widely accepted theory that the sudden death of Chokei's younger brother Kazumasa SOGO in 1561 and the death of Chokei's son Yoshioki MIYOSHI in 1563 were the results of poisoning by Hisahide.
しかし1561年の長慶の弟・十河一存の急死や1563年の長慶の子・三好義興の死は、久秀の毒殺説が有力である。