As descriptions in historical books that support this view, it is well-known that a section of 'Historia de Iapan' by Frois continued as, when Mitsuhide reversed the course to Kyoto, 'Soldiers began to wonder about the purpose of such action (to attack the Honno-ji Temple and thought that Mitsuhide intended to kill the lord of Mikawa Province (Ieyasu), who was a younger brother-in-law of Nobunaga, according to Nobunaga's order, and a section of 'Rojinzatsuwa' by Munetomo EMURA.'
裏づけとする史書の記述として、フロイスの「日本史」が続いて、光秀の京都への反転に際して「兵士たちはかような（本能寺を攻める）動きがいったい何のためであるか訝り始めおそらく明智は信長の命に基づいて、その義弟である三河の国主（家康）を殺すつもりであろうと考えた。」という部分がある。