Gaijin, a Japanese word, means outside person if the kanji (外人）are translated literally. This term only applies to people, not corporations as much as they would like to be people in that kind of Pinocchio "I'm a real boy" kind of way.
It also does not refer to life forms that come from beyond the borders of our atmosphere. The term only applies to homo sapiens who reside within the recognized borders of the nation called Japan who were not branded with the Japanese label at birth, or who have not appealed to government bureaucracies in order to be so branded later in life.
Gaijin is actually a shortened form of the word Gaikokujin.（外国人） This word refers to country or nation with the added koku character in the middle, and would be outside country person. However, when translated by the Justice Ministry of the Japanese government, one word is used, Alien.
I am an officially registered alien by the Japanese government. I carry a registration card which says that I am required to carry it "in person at all times." I am not required to wear special clothing or mark myself in any way, but my physical appearance is enough to suggest my alienness.
My appearance is enough to cause clerks in shops to run away, to sufficiently confer a feeling of entitlement on the parts of some people to ask me for language lessons or to inquire if I know of others of my kind who may be willing to teach a language.
It sis also sufficient to attract the interests of police officers who may ask if the bicycle I am riding is my own, or if they could examining documents that would confirm the obvious reality that I am an alien.
The creation of nation states is a method to protect the wealth and power of a few. This necessitates the creation of borders that slow the flow of goods inward. This allows the powerful to impose taxes on the inbound people and goods. The powerful claim that borders are essential for the protection of the residents' safety, and higher prices as a result of imposed taxes is claimed to be in the interest of public safety.
Borders are an excuse to erect physical or imaginary barriers, to impose taxes, and raise armies. They are in fact meaningless conveniences for a hegemony.
Those borders are meaningless in nature. They cannot restrict the flow of energy, plants, animals, human waste, weather, or time. In fact, they cannot even restrict the flow of the people and goods that they are intended to control.
I am an alien, and I recommend it as a lifestyle. The life of a terrestrial is a schizophrenic existence, where distinctions of inside or outside （内／外）us or them （内／他人）past/present/future, knowledge/ignorance, or legal/illegal haunt the residents.
The alien has no reason to consider these dualities. They have no bearing on our lives.
In Japan alienation is also closely associated with racism, in fact, most Japanese people do not make a distinction, assuming that a person of a race other than Asian is an alien. This assumption is often faulty, as people of any race can obtain Japanese citizenship, and not all Asians obtain Japanese citizenship.
This podcast is dedicated to the examination for Alienness and Aliens, especially those living in Japan.