Similarly to most other De-Matoran, Demu began his life on Spherus Magna. For a number of years, he aided in the early construction of the Matoran Universe with no worldly desires or true consciousness. Demu and the other inhabitants of his settlement were highly successful in thier living, and soon constructed many large metal structures, possible due to the large amounts of metal in the stone around them. They formulated a stable economy, built an aqueduct system and named their city De-Metru.