While resting by a lake with his friends, Ash polishes his Badge Case and remembers all the Gym Battles he's won so far. Suddenly, a wild Whiscash jumps out and eats the case. Ash dives in to go after it to get his badges back, but nearly drowns. He is saved by a Fishing Master named Sullivan who has spent years trying to catch the giant Whiscash. Determined to retrieve the badges, Ash and the others start fishing. Meanwhile, Team Rocket are also trying to get a hold of the same Whiscash.