Ruli, accompanied by Hiro and Kiyoshiro, visit a lake where there are rumors going around that kappas appear and drag humans underwater. Nearby, was a newly built factory. Even though Hiro says they will investigate in the morning, Ruli secretly goes out that evening with Angoramon and Espimon.
At the lake, Ruli sends Angoramon and Espimon to investigate around the area. While alone, she gets surrounded by a mist and pulled into the lake. Thankfully, Gawappamon save her from their boss, who wants to eat humans.
After recovering from the first ordeal, Ruli wants to go back to the lake. She believes that the Gawappamon are getting abused by their boss. When they get there, so many people are around. Ruli sends them into the Digital World when a man is snatched.
In the Digital World, they discover that it is Shaujinmon causing the problem. When he threatens to eat them all, the digimon partners evolve to fight.
The Gawappamon beg Ruli and the others to help their boss. He used to be kind and peaceful until the beads around his neck cracked. Even the Gawappamon cannot control their boss.
Angoramon Warp Evolution to Lamortmon!! He takes down Shaujinmon, and Thetismon repairs his cracked beads, as well as, the sick Gawappamon. Shaujinmon becomes the friendly digimon he was.
After the Gawappamon and Shaujinmon leave, Kiyoshiro discovered that there was a chemical leak from a cracked pipe of the new factory. This was causing water pollution and effected Shaujinmon and Gawappamon who live in the water. The factory promised that it wouldn't happen again.