Elpizo was formerly known as TK-31, working in Neo Arcadian Bureau of Administrative Services. In his career, he discovered lots of secrets about Project Elpizo. Later, Neo Arcadia later turned their back on innocent Reploids, labeling them as Mavericks under Copy X's orders. In the meantime, before he could join his fellow Reploids in awaiting execution, a surprise assault from the Resistance interrupted everything. TK-31 with his best friend HE-22 flee the vicinity.