Yamaguchi Keiji was turned by the Imagawa family and started a rebellion, which had a huge impact on the Oda Danjo Chonosuke household. After all, whether it was the Matsudaira family harassing them or the Oda main house in Qingzhou coming over to take advantage, those were all external threats—in Japan's Warring States Era, that was pretty normal. Aside from Harano, the modern man, no one batted an eye.
But when a senior household retainer like Yamaguchi Keiji betrays you, that's a whole different beast—this was an internal clan conflict. It meant a lot of people in Danjo Chonosuke's household had totally lost faith in Oda Nobunaga, figured there was no future following him, maybe couldn't even keep their own little clan safe, so it was time to find their own way out.
