Ageha is a complex figure whose life is defined by loss, survival, and a deep-seated desire for a better world. A former slave and one of the last survivors of the Blue Nobles, a nomadic people nearly wiped out by the ruling government, he carries the trauma of his past with a quiet, often unreadable demeanor. He is introduced as a wandering performer, known as Kicho, the star dancer of Madam Butterfly's traveling troupe, a guise that allows him to move freely across the country. Accompanying him is his owl, Kagero, who is the parent of Sarasa's own companion, Shinbashi.

From a young age, Ageha was a pleasure slave to an abusive noble, an experience that left him deeply scarred and emotionally guarded. The only person who showed him any kindness during that time was Shido, the nobleman's son, a fact that created a profoundly tangled relationship of love, hatred, and resentment that would follow him for years. His first fateful encounter with the series' protagonist, Sarasa, occurs when he saves her from the Red King, losing his left eye to the king's blade in the process.

Ageha’s personality is marked by a bitter apathy born from his suffering. He is described as caring about and believing in no one, not even himself, for a long time. This manifests as a rational, sometimes merciless, demeanor. He is not gentle; rather, he is someone who pushes others to their limits, forcing them to confront harsh truths and make difficult decisions, much like a bird pushing its chicks out of the nest. Despite his emotional detachment, he is highly perceptive, quickly deducing that Sarasa, the supposed Boy of Destiny named Tatara, is actually a girl. He operates as a voice of rationality, a source of information, and a deadly sword when needed, possessing a stunning array of skills including swordsmanship, subterfuge, diplomacy, and spycraft.

His motivations evolve throughout the narrative. Initially, he drifts without purpose, but he becomes involved in Sarasa’s cause not out of immediate belief, but because he wants her to prove that there is something in the world worth believing in. A prophecy once told him he would meet a woman worth dying for, and he seems to test this against Sarasa. Ultimately, his motivation transcends any single person; his ultimate goal is to help create an ideal country and change the course of history, a fight he dedicates his entire life to. This leads him toward an antihero stance, as he later works to eliminate the king’s allies with cold-blooded efficiency.

Ageha’s role in the story is that of a crucial, if enigmatic, ally to Sarasa. He acts as a guardian, a mentor, and a relentless challenger. He shelters Senju, the pregnant fiancée of his lost love Shido, and brings her to Sarasa’s group. He does this not only to protect her but to force Sarasa to confront the human consequences of her war and to ensure that Senju sees the humanity of her lover’s killers, so her child would not be born with the same hatred Ageha carries. He also silently observes Asagi, a dangerous spy, as he infiltrates Sarasa’s organization, choosing not to warn her because he believes she must be able to see through such deception herself to be worthy of her destiny.

Key relationships define his arc. His bond with Shido is the most twisted, a mix of deep affection and loathing, as Shido was both his protector and the son of his abuser, never truly seeing Ageha as an equal. After Shido’s death, Ageha finds a unique connection with Senju, loving her because she was loved by Shido, and becoming her lifelong protector. He also shares a brief but genuine romantic and sexual relationship with Aello, a woman from his own nomadic tribe, with whom he forms an emotional bond based on common ground. Ageha is undeniably bisexual, loving both men and women openly without the narrative vilifying him for it. His connection to Asagi is also notable, as Asagi shows a vulnerability with Ageha that he displays with no one else, leading to a relationship that could be interpreted as a deep friendship or something more ambiguous.

Ageha’s development is a journey from apathetic survivor to a man willing to die for a cause. He learns to believe in something larger than himself and to invest in the future. In a significant moment, he rejects Shido not just as a person but as a symbol of his past subjugation, affirming his own self-worth. His character arc concludes with his death, a selfless act where he single-handedly takes on a squadron of soldiers to clear a path for others, dying unaware of the final outcome but wholly focused on the goal in front of him. His notable abilities are vast; beyond his combat skills, he has friends and allies across all of Japan and can call in tremendous favors, making him a linchpin upon which much of the story’s turning points rest.