Maria is in love with Ralph's Tony. However, the intense rivalry between Emily and Tony caused to part the Nidorino. Misty decided to handle the problem and forced Emily and Tony to meet each other, but this still caused trouble. When Team Rocket took the Nidoran, Emily and Ralph decided to work together, as Tony and Maria defeated Team Rocket by working together. That resulted in them evolving into Nidorino and Nidorina.