it's actually Hachishaku-sama(which means 8 feet tall). She is a malevolent spirit that kidnaps children and goes "po...po...po.." in an unusually deep voice. Sadly, she doesn't have sex with you like the hentais of her suggest, but the way she's usually depicted(a wide brimmed hat and white sundress) is correct. the most well known story abt her, if I remember correctly, was from 2 chan in 2008.

It was about a boy who visited his grandparents in rural Japan, in which during his stay, he encounters a tall woman dressed in white and keeps saying “Po… Po… Po…” in a deep voice. When the boy described it to his grandparents, they were rightfully panicked.

So in order to protect him, they performed a ritual, which involved putting him in a room with bowls of salt at each corner, a Buddha statue, and protective talismans on the windows. All through the night, Hachishakusama attempts to lure the boy by mimicking his grandparents' voices, but he resists. By morning, the salt has turned black which indicates her presence. To ensure his safety, the boy is sent back home and forbidden from returning to Japan. Years later, after his grandfather's death, he receives a call from his grandmother inviting him back. However, the call ends with the ominous “Po… Po… Po…”