Maria is in love with Ralph's Tony while they were still a female and male Nidoran. However, the intense rivalry between Emily and Tony caused to part the Nidoran. 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, Misty scolds them for fighting each other which resulted both of their Nidoran are stolen by them as Emily and Ralph decided to work together.
Both of their Nidoran manage to fight both Jessie's Arbok and James' Victreebel with their powerful abilities such as Tackle, Scratch and Double Kick and finally defeats them with Fury Swipes. After Team Rocket is blasted off by Misty's Staryu who destroys the Meowth Balloon, Misty still scolds them because of their rivalry especially the love of both of their Nidoran. Ash decides to make a truce for them to make a new home for their Nidoran since they are neighbors, they agree. Both Tony and Maria finally getting close as they kiss which resulted in them evolving into Nidorino and Nidorina much to both Ralph and Emily's surprise knowing that both Nidorina and Nidorino are together.