"Sonic Soldier Borgman Madnight☆Gigs!" is a 12-episode OVA series that serves as a sequel to the original "Sonic Soldier Borgman" anime. The story is set in a futuristic world where humanity faces threats from the alien organization known as the Vahlstrom. The narrative centers on the Sonic Soldiers, a group of genetically enhanced warriors equipped with advanced combat suits called Borgman. These soldiers are tasked with protecting Earth from the Vahlstrom's incursions.

The protagonist, Ryo Hibiki, is a skilled Sonic Soldier who pilots the Borgman Liner. Alongside him are his teammates, including the determined and resourceful Anise, the calm and analytical Shogo, and the spirited and energetic Rina. Together, they form a cohesive unit dedicated to thwarting the Vahlstrom's plans. The series introduces new characters, such as the enigmatic and powerful Midnight☆Gigs, a group of rogue Sonic Soldiers with their own agenda. Their motivations and allegiances remain ambiguous, adding complexity to the conflict.

The plot unfolds as the Sonic Soldiers face escalating threats from the Vahlstrom, who deploy increasingly dangerous bio-mechanical creatures to achieve their goals. The Midnight☆Gigs complicate matters by interfering with both the Sonic Soldiers and the Vahlstrom, creating a three-way struggle. Themes of loyalty, identity, and the ethical implications of genetic enhancement are explored as the characters grapple with their roles in the ongoing war. The series balances action-packed battles with moments of introspection, delving into the personal struggles and relationships of the main characters.

As the story progresses, the Sonic Soldiers uncover deeper secrets about the Vahlstrom's origins and their connection to the Borgman technology. The Midnight☆Gigs' true intentions are gradually revealed, leading to unexpected alliances and betrayals. The climax involves a high-stakes confrontation that tests the resolve and unity of the Sonic Soldiers, culminating in a resolution that leaves lasting implications for their world. The series maintains a brisk pace, blending science fiction elements with character-driven drama to create a compelling narrative.