Entering Earth's atmosphere, the space monster Arigera came to attack the earth. Despite GUYS and Ultraman Mebius being deployed to stop it, its sheer speed was more than enough to make the space monster versatile and uncatchable by both heroes, until the monster was shot down into the ocean by GUYS Ocean .
Noticing that Arigera can emit frequency waves, GUYS used it to locate and trap the monster. Working together with GUYS Ocean, a game of "cat and mouse" is set up to drag the Arigera onto dry land in hopes of finishing it off. Once Arigera was marrooned onto dry land, it refused to go down without a fight proceeded to try and take down both GUYS' ships with its fireballs. Ultraman Mebius returned and both ultra and monster fought to a standstill. Ultimately, Mebius won by pulling out his Mebium Blade and slicing Arigera right down the middle. The two half's floated for a second before exploding