I-Machine - that is the general term for large robots that work in extreme environments. Maya Mikuri, a student at the Union Academy, was involved in an accident while using an I-Machine. She was helped by the spaceship of the Escavite Company, which was driving the I-Machine and mining the Orichalcum ore like a pirate. She ended up working as a member of the company... While living among the members with their own characteristics, Maya gradually began to understand what "human" is. Hidden in the lost memories is hope or despair.