"Momogumi Plus Senki" is a fantasy manga series set in a world where humanity faces constant threats from monstrous creatures known as "Kegare." The story centers around Momotarou, a young boy who wields a legendary sword and is destined to lead the Momogumi, a group of warriors tasked with protecting the world from the Kegare. The narrative begins with Momotarou's arrival in the capital city, where he is introduced to the Momogumi and its members, each possessing unique abilities and weapons tied to their roles in the group.

The Momogumi operates under the leadership of Princess Kaguya, who oversees their missions and provides guidance. The team includes characters such as Kintarou, a strong and loyal fighter; Urashima, a skilled archer with a calm demeanor; and Hiko, a mysterious and powerful warrior. Together, they embark on missions to combat the Kegare, which are born from human negativity and corruption. The Kegare manifest in various forms, each requiring strategic approaches to defeat.

As the story progresses, Momotarou's leadership is tested as he learns to balance his responsibilities with his personal growth. The series explores themes of camaraderie, duty, and the struggle against inner darkness, as the Momogumi members confront their own fears and flaws while battling external threats. The Kegare's origins are gradually revealed, tying their existence to the emotional and moral struggles of humanity.

The narrative also delves into the political and social dynamics of the world, with factions vying for power and influence. The Momogumi's role as protectors places them at the center of these conflicts, forcing them to navigate alliances and betrayals. The series builds toward a climactic confrontation with the source of the Kegare, challenging the Momogumi to unite and harness their collective strength to save their world.

Throughout the story, the characters' relationships and individual arcs are developed, highlighting their growth and the bonds they form. The series combines action, fantasy, and emotional depth, creating a layered narrative that balances intense battles with moments of introspection and character development.