The Anime Story
We first meet this scientist in a dark laboratory where he commands his assistant Kaolinite to find a person with a pure heart. He is in search of the three Talismans that could form the Sacred Cup and those talismans sleep within the three humans with pure hearts. He gives her a daimon egg and the assistant goes on her way. Repeatedly she fails and finally she is defeated by the soldiers. The professor then calls upon the Witches5 and one by one they fight for him. It is later discovered that he is the father to Tomoe Hotaru, Chibi Usa's new found friend. His daughter is to become the Deathbusters' Messiah of Silence and call upon their master, Pharoah90. When Mistress9 (Hotaru's body is taken over by Mistress9) takes form she commands the Professor. When confronted by Sailor Uranus and Sailor Neptune Tomoe is released by the creature that possessed him. He was merely a container for the daimon Gelmatoid. This creature is quickly defeated and Tomoe goes in search of his daughter. Mistress9 pushes him away but when she begins to break down he embraces the girl. He begs Sailor Moon for the Sacred Cup to help save his daughter (he genuinely has no memory of what when on while possessed). After the tragedy of the battle is over and Hotaru's body turns to that of a child we find that Tomoe is in a hospital and that he might never regain his lost memory of when he was possessed. His baby girl is returned to him and they live together again.
In the Sailor Stars part of the anime, he makes an appearance. He is with his baby daughter Hotaru once again and they are in his mansion. Meioh Setsuna comes to take Hotaru with her. At this point we really don't know what happens and what was said between the woman and Tomoe but we know that Hotaru ends up being taken in by Setsuna, Michiru, and Haruka in their mansion. This was his last anime appearance.
The Manga Story
Professor Tomoe was obviously a scientist and owned the Mugen Academy. At a lab one day there is an explosion and a fire breaks out. He and his daughter are injured very badly. To save his daughter's life he agrees with the entity who appears to him at that moment (Pharoah90) that if he saves her life he will work for him. His love for his daughter is apparent here as he agrees to sell his soul to save her life. The bad part about the whole mess is that when this happened his daughter's body was inhabited by a being as well. After he is released from his possession you once again see how much he cares for his daughter, even in the form of Mistress9.
Professor Tomoe's Tiny Shrine