Nano is a series of science-fiction Shoot 'em Ups by Shin'en Multimedia. The series is one of the few shmups to appear on the Nintendo DS and 3DS, and is in many ways a spiritual successor to Iridion II, also by Shin'en. The series focuses on the Nanostray, an artificial virus which infects both machines and living beings, with the pilots in each game being sent to investigate outbreaks of the virus. Despite the plot connection, each games features a different gameplay from each other.