The Known Universe, more colloquially known as the Knowniverse, refers to the region of outer space known to mankind. It is limited to the cluster of five star systems colonised by humans in the 29th century. The planet Benzaiten is the centre of the Known Universe, and the political, economic and cultural capital, and the first planet to be colonised by humans. Apart from Benzaiten, there are a further nine habitable planets, Raijin, Yosuzume, Yuki Onna, Kojin, Daikoku, Oinari, Tohuku and Sujin.