Ash and his friends come to Dark City, a place where innocent citizens are afraid of Pokémon trainers, because of the gang wars going on. Two rival groups, Yas and Kas, are both competing for the right to become Dark City's gym, and are causing damage to their city in their fierce rivalries. Team Rocket get caught up in it, fighting for Kas gym.
Ash decides to put a stop to this, and with some of the city's children's help, plays on the fact that the Kas and Yas leaders use Scyther and Electabuzz, both of whom go mad when seeing the colour red. Dumping vats of red ketchup on the leaders, their own Pokémon turn on them. Then Nurse Joy, who is the Pokémon League representative, tells the two gyms that NEITHER will be the town's official gym because they cannot use their Pokémon right or respect each other. She has them ask Ash for help, as he understands Pokémon, but he is not a good teacher. ^_^;