Ano Ko wa Toshi Densetsu.

There is an urban legend about a mysterious girl known as Zangyaku-san, a supernatural figure who serves as a dark guardian against those who prey on the innocent. She appears throughout the city, delivering swift and otherworldly justice to those who deserve it most, leaving them in a state of eternal rest. When she encounters a particular individual who fits her criteria for punishment, something unexpected happens - her usual methods prove ineffective against him. This chance encounter sets off a dangerous game between the two, as their paths continue to cross in increasingly tense confrontations. What begins as a simple tale of supernatural justice evolves into a complex psychological thriller, exploring themes of identity, obsession, and the blurred lines between hunter and hunted. The story delves deep into the nature of punishment and revenge, taking readers on an emotional journey through a dark urban fantasy world where nothing is quite as it seems.