Munemitsu MUTSU heard that Kyutaro MIURA, a feudal retainer of the Kishu Domain, who was an influential supporter of the bakufu, together with Itsuzo IDA of the Ogaki Domain and others were plotting something threatening in Kyoto and that the Kishu clan was the mastermind of the assassinations of Ryoma SAKAMOTO and Shintaro NAKAOKA (Omiya Incident), which occurred in retaliation for the Iroha Maru Incident from which they had a grudge against Ryoma.
陸奥宗光は、当時有力な佐幕論者であった紀州藩士三浦休太郎が大垣藩井田五蔵らと共謀して京都にて不穏な動きをしていること、また、坂本龍馬、中岡慎太郎の暗殺（近江屋事件）が、伊呂波丸事件にて龍馬に恨みを持つ紀州藩が黒幕であるとの話を聞いた。