Professor Tomoe

Souichi Tomoe is Hotaru's father, a scientist and the owner of Mugen Gakuen. When Hotaru was at a very young age, she was severely injured during an explosion at her father's laboratory. Professor Tomoe allowed an evil entity known as daimon Germatoid to possess his body in order to save his daughters life. He first appears in episode 90 as the leader of the Death Busters, hunting for pure heart crystals and to ultimately prepare for the awakening of Master Pharoah90.

Once daimon Germatoid leaves his body in order to fight Sailor Uranus and Sailor Neptune, he becomes good again.

Daimon Germatoid

Daimon Germatoid possessed Professor Tomoe and is the only male daimon. He creates all the other female daimons to work for him, who ultimately become the 'monsters of the day' in the third season. He is killed by Sailor Uranus and Sailor Neptune.

Kaolinite

Kaolinite is Professor Tomoe’s loyal assistant. She uses daimon to search for the three Pure Heart Crystals which contain the talisman, but occasionally attack her enemies herself using her hair. She is killed after falling off Tokyo Tower but is later revived by Professor Tomoe as Kaoli.