Sōichi Tomoe was a professor in the science of DNA manipulation. He is also the founder of the Mugen Academy. One day while overlooking an experiment, the DNA machine exploded killing everyone except him. Crying over his daughter's dead body (Hotaru), a voice was heard and an entity known as Germatoid appeared before him. It offered to save his daughter as long as accepted his conditions. Tomoe would do anything to have his daughter saved, so he agreed. Not being told the conditions, Tomoe was possessed by Germatoid, entering into his right eye and Hotaru was saved but possessed by another entity that found its way into this dimension, Mistress 9 (Messiah of Silence). Tomoe now became the leader of the Death Busters, and sent out his followers to collect Pure Hearts so they could revive the Messiah of Silence so that they could take over this dimension. Tomoe was released from Germatoid's control once he no longer had a use for his body. Tomoe was left with amnesia but was able to start his life again with Hotaru who had been reborn after using her ultimate attack as Sailor Saturn to destroy Pharaoh 90.