Defeated at Katezu.Japan's ceiling decided to avoid the mountainous area and St. Reagan, which gathered in the south, and decided to cross Lake Baikal. Meanwhile, Gainer enjoys playing games at Domepolis near Lake Baikal, and communicates with his online game friend "Cynthia" for the first time in a while. On the other hand, Asham and his friends, who were gathering troops aiming for Kidz Mund's castle, Liman Megalopolis, were attacked by Kidz Mund's treasured Overman Dominator, and were in danger of being annihilated. The aftermath of the battle reaches the ceiling of Yapan, and Gainer sorties to stop the Dominator.