Izuso the Blade is a warrior passing through Izumo who defeats Youkai. The one problem that she has though is that she is not good at fighting huge Youkai. As she is attempting to walk through Izumo to get to Kyoto, she finds herself unable to get past Yagyou-san. She notices a passing Oni, the player, and asks for his assistance in distracting the Yagyou-san while she makes a dash for the entrance to Kyoto. After finding safe passage into Kyoto, she thanks the player for his help and continues on into Kyoto.
Izuso the Blade can first be found in West Izumo, until the player starts the quest "Can't Beat the Yagyou". During this quest, she will move to the entrance of Kyoto in South Izumo, where she will then disappear once the quest has been completed.