Ikki Kurogane, a student at Hagun Academy, is considered the weakest knight in his class, earning the derogatory nickname "Worst One" due to his low Blazer rank. Blazers are individuals who can manifest weapons from their souls and wield supernatural abilities. Despite his perceived inadequacy, Ikki possesses exceptional swordsmanship and determination. His life takes a dramatic turn when Stella Vermillion, a prodigious princess from a foreign kingdom and the top-ranked student at the academy, becomes his roommate. A school rule dictates that roommates must duel, and the winner gains control over the loser’s life. In a surprising turn of events, Ikki defeats Stella, but instead of exploiting his victory, he treats her with respect, sparking a mutual admiration and deepening bond between them.

As the series progresses, Ikki and Stella navigate their evolving relationship while facing challenges within the competitive environment of Hagun Academy. The school prepares its students for the Seven Stars Sword Art Festival, a prestigious tournament where the strongest knights compete for glory. Ikki’s journey is marked by his struggle to prove his worth in a system that undervalues him, while Stella grapples with her own insecurities and the weight of her royal responsibilities. Together, they support each other, growing stronger both as individuals and as a team.

The narrative explores themes of perseverance, self-worth, and the importance of mutual respect in relationships. Ikki’s encounters with other students, including his rivals and allies, further develop the story’s dynamics. Characters like Shizuku Kurogane, Ikki’s devoted younger sister, and Nagi Arisuin, a gender-fluid and enigmatic classmate, add depth to the ensemble cast. The series balances action-packed battles with moments of emotional and romantic development, creating a cohesive blend of shonen and romance elements. Through its focus on personal growth and the bonds formed between characters, "Chivalry of a Failed Knight" delivers a compelling narrative centered on overcoming adversity and defying societal expectations.