They notably play a bigger role in the Yo-kai Watch Jam: Yo-kai Academy Y series, acting as the main antagonistic faction and conflict. Mazera is known to be the leader of one of the most known and widespread aliens, which range from canine creatures to human vessels corrupted with Mazera's mind-bending powers.
It is unknown if the aliens have a connection with the Members of the Mikakunin Tribe, despite sharing similar appearances and having a similar UFO design to the one Mazera's force uses.
Akihiro Hino was inspired by the 1989 video game Last Armageddon when he made the Aliens as the main antagonists of the Yo-kai Academy Y series. He also wanted to make the player fight something that the player doesn't come across normally in another dimension.
Despite typically referred to as "Uchūjin" in the Japanese anime, Aliens can also be referred to as "Eirian" (エイリアン), or "Seijin" (星人).
Despite being framed as the main antagonistic faction of the Yo-kai Academy Y series, multiple of the aliens have joined forces with the YSP Club, the most notable being Nayu Kuruhoshi.