OVA
Description
Mike Sounders XIII is a Super AI robot created by NASA, designated as model number XCR-13, which stands for Experimental Cosmo Robo. He is the thirteenth unit in the Mic Force, a series of identical robots with twelve older brothers. In his initial Cosmo Robo form, he appears as a small, blocky red and blue robot with a monitor for eyes that can display a wide range of emotions, sometimes even showing an image of GaoGaiGar when he feels brave. He pilots a yellow flying vehicle called Baribarien, which can transform into a mobile stage known as Studio 7. Later, Mike Sounders XIII gains the ability to transform into his true form, the Boom Robo, a taller red and blue robot designed after a rock-and-roll singer. In this form, Baribarien becomes Studio 7, which produces his musical combat equipment, including the Dazzling VV keytar, the Thundering V microphones, and the Sparkling V harmonica.

His combat abilities are entirely based on sound manipulation. The programs for these attacks are stored on various discs housed in Studio 7. He uses general-purpose discs such as Disc M and Disc P, the more dangerous Disc X, and later the even more powerful Disc F. His signature technique is the Solitary Wave, a devastating sonic attack. Mike Sounders XIII initially appears having escaped his containment unit. He makes his way to a radio-controlled robot competition where Mamoru Amami is participating. During his early appearances, he serves as a source of comic relief, repeatedly trying to fly into dangerous situations to assist GaoGaiGar only to be knocked far away. He is eventually properly retrieved by the Gutsy Geoid Guard (GGG) and introduced to the other Braves. Despite his comedic beginnings, he is persistent and eager to help, and he gradually proves his bravery and worth.

As the story progresses, he takes on a more serious role. He participates in key battles, such as helping Dr. Raiga stall the enemy EI-01 long enough for GaoGaiGar and other Braves to launch a counterattack. By the time of the final confrontation against the Z Master, Mike Sounders XIII has developed into a more capable fighter. During that climactic battle, he fires the Solitary Wave again at the Z Master, but the attack is countered. In the exchange, all twelve of his older brothers are killed, leaving him as the sole survivor. Enraged and swearing revenge, he continues to clash with the enemy. Mike Sounders XIII has close ties with the other members of GGG, particularly GaoGaiGar and Mamoru, and his experiences transform him from a clumsy comic figure into a determined warrior who fights alongside his comrades until the very end.