Definitely not. Ju-on is a product of imagination and horror fiction. It doesn't draw from any actual true incidents. The scares and plotlines are all made up to thrill and spook the audience.
Ju On is purely fictional. It's crafted by the imagination of the filmmakers and writers to create a terrifying horror experience. There's no real-life basis for the events depicted in the movie.
Yes, 'Ju-on Origins' is based on a true story. It draws inspiration from the Japanese horror folklore about the curse of the Ju - on house. This curse is said to bring death and misfortune to those who enter the haunted house.