Koyo Gunkan states that 'just when the Imagawa army thought they had won the battle (another previous battle) that day and went off for looting, the Oda army was mixed up in them and took Yoshimoto's head,' while another historical source confirms that Ieyasu TOKUGAWA was quoted as saying 'the Imagawa army was looting, and caught off guard.'
甲陽軍鑑には「その日の（事前にあった別の）戦いに勝ったと思った今川軍が略奪に散る中、織田軍が味方のように入り交じり、義元の首を取った」とあり、又別の史料で徳川家康が「今川軍が略奪し、油断していた」と証言したのも確認。