Yōkai are a series of supernatural being that process ranges of power. Yōkai are know to give off an energy field or aura called Yōki. Yōkai monsters ranges from a simplistic monsters like the umbrella like those of Kozo Kasahara to those powerful Shinso Vampire like Alucard. Yōkai monsters have an ability to switch between their monster form and a Human form to hide from the Human population. Yōkai monsters live in a dimensional realm known as the Monster World.
- See Also: Monster Classes
- A lot of monsters shown in Rosario+Vampire aren't even a Yōkai, examples being Vampire and Werewolf.
- Yōkai roughly translates as "supernatual people".
- Monster is the term any of the yōkai beings were slandered with following one too many offenses by humans, hence their disguises and their general loathing of human in general.