"Lime-iro Ryuukitan X" is a 12-episode anime series set in an alternate historical timeline where Japan faces a looming threat from a mysterious enemy known as the Western Federation. The story unfolds in a world where advanced technology coexists with traditional elements, blending steampunk aesthetics with historical fiction. The narrative centers around a group of young women who are part of a secret military unit called the "Lime Team," tasked with piloting advanced mechanical weapons known as "Ryuu" to defend their nation.

The protagonist, Airi Komiyama, is a determined and skilled pilot who joins the Lime Team after her family is tragically affected by the ongoing conflict. Alongside her are other key members of the team, including the calm and strategic Kaede Shiranui, the energetic and impulsive Ayano Kosaka, and the reserved yet highly capable Karen Ayanokouji. Each character brings unique skills and personalities to the team, contributing to their dynamic as they face increasingly dangerous missions.

The plot progresses as the Lime Team engages in battles against the Western Federation, uncovering secrets about their enemies and the true nature of the Ryuu technology. The series explores themes of camaraderie, sacrifice, and the moral complexities of war, as the characters grapple with their roles as soldiers and the personal toll of their missions. Tensions rise as internal conflicts within the team and external threats from the Federation test their resolve.

As the story unfolds, the Lime Team discovers that the Western Federation's motives are more complex than they initially appeared, leading to revelations about the origins of the Ryuu and the broader geopolitical landscape. The series balances action-packed sequences with moments of character development, delving into the personal histories and motivations of the main cast. The narrative builds toward a climactic confrontation that challenges the team's unity and forces them to confront the consequences of their actions.

"Lime-iro Ryuukitan X" combines historical and fantastical elements to create a unique setting, with a focus on the interplay between technology and human emotion. The series maintains a steady pace, blending episodic missions with an overarching plot that ties the characters' personal journeys to the larger conflict. Through its exploration of war and identity, the anime offers a compelling narrative that keeps viewers engaged until the final episode.