Asahi, Katsumi, and Isami regroup and talk to each other after a very fierce fight. They talk about how they first found the R/B Gyro, how they first became giants of light, and how they’ve overcome countless challenges along the way. Meanwhile, their father, Ushio, searches his family chest in attempts to remember the good times. But his anxiety manifests itself in a single word…

Asahi reveals to her brothers Saki Mitsurugi’s past, who had just stolen from them their own R/B Gyro’s! Katsumi somewhat sympathizes with Saki, while Isami is actually angry at her. Suddenly, the kaiju Gomora appears in the city! When Katsumi sets out to take back his R/B Gyro from Saki however, she transforms herself into Grand King Megalos, and stands before them! Katsumi and Isami are both in trouble now that none of them can transform…

The battle between the two Ultra Brothers and Saki Mitsurugi, who transformed into a kaiju, was long and hard with no clear winner. But shortly afterwards, Saki visits the two brothers at Quattro M! Although Katsumi proposes that they all work together to save the world from destruction, Saki refuses to respond, and instead begins to tell them the story behind their mother, Minato Mio’s disappearance! And an inescapable, centuries-old battle will start once again…