Kosei challenges Sorato to a fight as part of his battle training with Rekiness, Trigaron, and Valgeness. But their training ground deep in the mountains turns out to be the Alien Barossa Zahgon's lair and he covets their treasure... the Meteokaiju?! Zahgon captures Sorato and Kosei, then a mysterious girl named Gilda appears in front of Kosei.