Hanachirusato is an NPC in Inazuma appearing exclusively during the questline "Sacred Sakura Cleansing Ritual".
She appeared as a normal shrine maiden with her face hidden behind a fox mask. It was explained that Hanachirusato was part of the condensed "filth" that inherited the memories of the late Kitsune Saiguu and decided to carry out the latter mission despite the natural outcome.
She vanished after the questline, leaving behind her mask as a diagram for a catalyst.
Although her face was never shown, her mask is said to be deeply stained by corruption on the inside.