Steam Detectives - Season 1 Episode 2 The Challenge of the Crimson Scorpion

On his way home, Narutaki sees a young girl kidnapped. He pursues, and eventually frees the girl. When her father comes to get her, they learn that he is a scientist, working on a powerful new power source that could do away with steam energy forever. The assumption is made, that Gina was taken to trade for her father's research. Soon, the girl is taken again, and this time a ransom demand is made- the kidnappers indeed want the meteronite, the crystal energy source her father is developing. A trade off is setup, but at the last minute, Narutaki realizes it is a double cross- Gina's live in tutor is actually the Crimson Scorpion, a thief desiring all beautiful things for herself.