The term yūrei encompasses a wide range of yōkai. They used to be humans, but they became creatures somewhat like the Western concept of ghosts in death. The appearances of specific types of yūrei tend to be based on how they died or why they have returned to Earth. For example, ubume used to be pregnant women, but upon dying they became a yōkai resembling a woman carrying a baby.

Yūrei that do not fall under a specific subtype of this variety of yōkai tend to have a handful of traits in common. They wear white clothes, have long black hair which is often messy, have hands that dangle limply from their first, and lack legs and feet, instead floating midair. They are often followed by hitodama, floating balls of fire that resemble will o' the wisps. These hitodama are often eerie colors such as blue, green, or purple.

FUN FACT: Hitodama can also exist independently from yūrei as souls of the dead that have become separated from their bodies. When they accompany yūrei, they are a part of that yōkai instead of independent entities.

Yūrei tend to linger were they died or where they were buried. Some are benevolent, while others are extremely dangerous. It depends on the specific type of yūrei, although the most widely known, generic ones are best known for haunting people and potentially bringing bad luck.

A yūrei will cease to exist if the person's soul finds peace. This can involve doing a variety of things from performing the proper funerary rites on the yūrei's earthly remains to enacting revenge upon the person's killer. Again, it varies on a case by case basis.

Examples of kinds of yūrei include zashiki warashi, kuchisake-onna, and a wide variety of other yōkai. For more information about specific types of yūrei and examples of them in various media, please visit their various entries in this guide.