A high school student named Yuta is on his annual class trip, hoping to finally confess his feelings to his crush, Shirayuki. Before he can, his entire class is suddenly summoned to a fantasy world where war is waged using humanoid mechanical weapons called Magic Suits. These suits are powered by an innate energy known as the Ludea Rate, and the people of this world have discovered that humans from Earth possess exceptionally high Ludea potential. As a result, Yuta and his classmates are declared property and sold into slavery. During the assessment, Yuta’s Ludea Rate is measured at a paltry 2, making him seem utterly worthless. While his friends and classmates are auctioned off for massive fortunes, Yuta is sold for next to nothing, purchased for the equivalent of two pieces of fruit.

This lowly beginning is a deception. Yuta’s power level is not low; it is so astronomically high that the measuring device malfunctioned, spinning off the charts. He is soon bought by a cruel master but quickly escapes with a fellow slave, a girl named Nanami who was sold into servitude by her own mother. During his escape, Yuta encounters a mysterious white Magic Suit that responds only to him, unlocking his hidden, overwhelming strength. From there, his journey becomes one of survival and discovery as he navigates a world that discarded him, taking on odd jobs that are impossibly easy for someone of his alleged standing.

The core cast includes Yuta, whose kind and unassuming nature belies his incredible power; Nanami, a resilient girl who becomes his first true companion; Shirayuki, his classmate and crush who was sold to a different master and seems to be in a comparatively better situation; and Nagisa, another classmate who harbors secret feelings for Yuta and is navigating her own enslaved circumstances. The ensemble is rounded out by Falma, an isolated girl with cat-like features who joins Yuta’s group later, and their homeroom teacher, who was also summoned and is determined to reunite her students and return them all to Earth.

The initial narrative arc focuses on Yuta’s immediate escape from slavery and his awakening as a powerful Magic Suit pilot. Subsequent arcs follow multiple perspectives simultaneously, contrasting Yuta’s underdog rise with the difficult experiences of his classmates in different households and countries. The story establishes a potential love triangle between Yuta, Shirayuki, and Nagisa, and builds toward a larger conflict as the various characters’ paths are set to collide with the ruling powers that rely on the earthling slave trade. The series explores themes of unjust social hierarchies and the use of advanced ancient technology in modern warfare, all while maintaining a fast-paced, action-oriented tone.