Kaiju and Seijin, Monsters and Aliens

If you like tokusatsu, you have probably heard of terms like Kaiju and Seijin. Their translations in English are not always entirely accurate, and some people might misunderstand the definition of them. Read on to find out more about the categories of villains.

Alien Baltan Jr. (Barutan Seijin Jr.) an example of an Uchujin

Seijin (星人) refers to beings from other planets. It is commonly translated as "alien". It literally means "star-person/people". Seijin itself is not commonly used on its own. There is always the planet it comes from as a prefix. (Eg. Baltan Seijin). Before tokusatsu, specifically before the Ultra Series, aliens were seldom written in English in such a way as "Alien __ ". For example, Alien Zetton would have been expressed as Zettonian in the western way of naming aliens. When one talks about them as a broad term, it will be called 宇宙人 (Uchuujin) meaning "space person".

Technically, Aliens do not have to be seijin. The English term "alien" can describe anyone that is not from our place, including alternate dimension entities and even...foreigners from another country.

Blacker, a Daikaiju

The word Kaiju (怪獣) is often translated as "monster" which is quite correct, but the literal meaning of it is "strange beast". When we think about kaiju, towering monsters like Godzilla or Red King come to mind, however, as stated above, kaiju includes any "strange beasts", ranging from seijin to things like bigfoot. Giant monsters are specifically refered to as Daikaiju.

Meanwhile, there is another group of villains known as Kaijin (怪人) which refers to humanoid monsters that are commonly found in Kamen Rider. The literal meaning of this is "strange person", or "monstrous person". This term can also be used for things like cryptids and phantoms, leading to some translations to refer to kaijin as phantoms. Kaijin can be seijin from outer space too, like DeUmon Kaijin from Triple Fighter.

There are some also Seiju, which are actually Stellar Beasts or simply put, space monsters. Then there are Robots and Cyborgs. Because there are so many types of villains, keep in mind that what I have written is just a guide but there is no perfect way to categorise them.