The answer to this question is both No and Yes. There is no singular evil kami in Shinto, nor is there a set , identifiable kami equivalent to Mara. The term Kami refer
…s to any sort of essence or force in nature, like that of a spirit or a deity. Everything can have a kami because everything has an essence. There are different types of kami just like there are different types of spirits. For example, there are greater, or "heavenly," kami which are the kami that we would commonly identify as a deity, spirit or god. There are lesser kami, like the kami of deceased individuals. There are also earth kami, fire kami, water kami, death kami, etc. Basically there is a kami for just about everything. "Kami" can mean anything from a sun goddess (like Amaterasu-o-mi-kami) to the essence of a rock. This being said, in an of themselves Kami can be either good or evil. There are different types of evil kami, demons, and spirits in Shinto. For example, mizuko are the spirits of dead children that roam the earth causing discord and bringing misfortune. Aragami are very powerful, evil kami that come to seek revenge for some grudge they died with. Oni are powerful supernatural demons that can be considered either good or bad and are sometimes considered a subcategory of Kami. There are three types of Oni: good Kami, evil Kami, and foreign Oni. The answer to this question is based on two particular Kami: Yomotsu-o-kami and O-Magatsuhi-no-Kami First: The most important realm for evil Kami is Yomi-no-kuni, the netherworld (aka the Shinto version of Hell). The principle kami of Yomi-no-kuni is the Yomotsu-o-kami , or "Greater Deity of Yomi." She rules over the netherworld as a principle "death kami." Even though she is basically the Queen of Hell, she is NOT an "evil" Kami the way Western ideology views Satan ruling over Hell. In Shinto, a spirit can be a demon and still NOT be evil. She is given a much more demonized appearance than other Kami but her function is really just as a death kami: She is a Kami that is inevitable but not necessarily good or evil, just like the other Oni, or "demons." Second: The Magatsuhi-no-kami are evil kami that bring about all forms of evil and disaster and reside in Yomi. There is a certain Magatsuhi-no-kami that bears the title of O-Magatsuhi-no-Kami and this means "Great Magatsuhi God" or, more importantly for the purposes of this question, "Great God of Evil Things." So, the two aforementioned titles of different Kami are the closest thing in Shinto to what Mara would be for Buddhism. *HOWEVER, AS YOU CAN SEE IN THE DISCUSSION ABOVE, THERE ACTUALLY IS NO ONE, SET, NAMED KAMI THAT CAN BE IDENTIFIED AS AN EQUIVALENT TO MARA. RATHER , THERE ARE MANY, MANY EVIL KAMI OF ALL DIFFERENT TYPES AND NAMES THAT ALL FUNCTION IN DIFFERENT WAYS BUT SOME OF WHICH CAN POSSIBLY BE SEEN AS DOING SIMILAR THINGS OR HAVING SIMILAR ROLES TO MARA . * ****Please Note:**** 1. This by no means is a comprehensive list of all the types of Kami and their categorizations. There are literally millions of kami (both good and evil) and this is simply a brief discussion of only certain subsets of evil Kami for the premises of answering the above question. 2. The Yomotsu-o-kami was formerly known as Izanami-no-Mikato, the female kami creator. It is only after her death and descent to Yomi that she achieved the title Yomotsu-o-kami. She can be referred by her name or by her title interchangeably. ( Full Answer )