Arian is a country featured in the Gundam Build Fighters series. Situated partially inside a Space Colony, Reiji, the crown prince, came to Earth from here. Arista, and thus Plavsky Particles, also originated from Arian.
Reiji described Arian as a peaceful and colorful country, on another world. When Reiji claimed to be the crown prince of Arian, Sei refused to believe him.
After the giant Arista was destroyed, Reiji, Aila, Chairman Mashita and Baker were transported to Arian where it was revealed to be partially in a space colony.