If any horror movie has a cult following it’s The Ring. As you may know the 2002 film and later sequels we’re based on a 1998 Japanese film called Ring. Ring in turn was based on 1991 novel by Koji Suzuki called Ringu. All tell the story of a cursed video that depicts a girl trapped in a well and anyone who watches the video dies in seven days. But what you probably don’t know is this girl with serious issues has deep origins in Japanese mythology. 
Japan has a huge collection of spiritual monsters called YokaiYokai are the spirits the Japanese believe surrounded the everything in the physical world. They can be anything from the stereotypical ghosts to fox spirits that like to light fires called kitsune, and trolls armed with giant clubs called oni. Often malevolent ones are the result of a soul that was disrespected and now want revenge. Yokai are also ussaly  attached to a certain place,object, or people.

Examples of Yokai

One such famous Yokai is the kyokotsu a ghostly girl in a white kimono with long hair that is spirit of the bones of a body that was thrown in the well. It precededs to haunt the well waiting to curse anyone who just happens to use it. One famous kyokotdu is Okiku who was thrown down a well after refusing to marry a particularly presistent samurai. Stories of Kyokotsu date to at the least Edo era Japan with famous author Toriyama Sekien

A woodprint of the kyokotsu

Woodprint of Okiku

So we know that The Ring’s demon of dampness is a Kyokotsu but what about the cursed movie part, did Koji Suzuki just make that up? Maybe but maybe not. In 1910’s Japan there was the curious case of a psychic named Ikuko Nagao. She claimed to be able to place images on the photo plates of old cameras with just her thoughts. Her story caught the interest of a professor at Tokyo university named Tomokichi who wrote a book in 1913 called Clairvoyance and Thoughtography about her powers being real. Most think  Nagao and Fukuari faked the results but the story caught lots of attention across Japan. 
So the creativity of Koji Suzuki is in merging very old folklore with a bizarre story from the early 20th century to create a horror novel that captures the idea of the modern urban legend .The ring perfectly illustrates how looking back can be the best way to innovate and creep millions out in the process. 
Sources
Ringu summary
https://h2g2.com/edited_entry/A6951657
Information on kyokotsu
http://matthewmeyer.net/blog/2016/10/30/a-yokai-a-day-kyokotsu/
Information on thoughtograpthy
https://en.m.wikipedia.org/wiki/Thoughtography