"Armored Trooper Votoms Case;Irvine" is a two-episode OVA set in the "Armored Trooper Votoms" universe, serving as a side story to the original series. The narrative centers on Irvine Lester, a former soldier and skilled Armored Trooper pilot, who becomes embroiled in a conflict involving a powerful and mysterious artifact known as the "Secret Society's Treasure." The story unfolds on the planet Melkia, where Irvine, now a wandering mercenary, is hired by a client to retrieve the treasure. However, the mission quickly escalates into a larger struggle as rival factions, including the Melkian military and a secretive organization, vie for control of the artifact.

Irvine's journey is marked by intense battles, political intrigue, and personal stakes. His past as a soldier and his connection to the treasure add layers of complexity to his motivations. Along the way, he encounters allies and adversaries, including a young woman named Kan Yu, who becomes entangled in the conflict. The narrative explores themes of loyalty, survival, and the consequences of war, all while maintaining a focus on the gritty, mecha-driven action that defines the "Votoms" franchise. The OVA provides a self-contained story that enriches the broader universe, offering insight into the struggles of individuals caught in the crossfire of larger power struggles.