TV-Series
Description
Aki Mikage is the twin brother of the protagonist, Aya Mikage, and a central figure in the story's tragedy. Born on September 24, he is sixteen years old and stands 177 centimeters tall. With brown hair and purple eyes, he shares a striking resemblance to his sister, reflecting their identity as twins.

At the start of the narrative, Aki is portrayed as a kind, gentle, and considerate individual, notably caring towards his sister Aya. He appears to be a typical teenager with hobbies like listening to music. However, this surface personality is gradually eroded as he is subjected to the experiments of the powerful Mikage corporation, the family to which he and Aya belong. These experiments are designed to awaken the latent spiritual powers within the family's descendants.

The core of Aki's character is his role as the reincarnation of Mikagi, the original progenitor of the Mikage clan and the husband of the celestial maiden, Ceres. The experiments conducted by the corporation awaken this past-life personality within him. The progenitor's persona is aggressive, blunt, crass, and obsessive, driven by a singular goal to find and reclaim Ceres, whom he calls "his woman". As this ancient personality gains dominance, Aki loses control of his own body and mind, becoming a vessel for a millennia-old evil. His transformation is marked by a shift in behavior, and the progenitor is depicted as bloodthirsty and willing to commit violence, such as when he kills the Mikage family patriarch. In this state, he aggressively pursues Aya, recognizing Ceres within her.

His primary motivation becomes twisted by this internal conflict. While the original Aki is motivated by affection for his sister and his friend Toya, the progenitor's awakening drives him to find and possess Ceres. This creates an incredibly tragic dynamic, as the kind brother is pitted against his own twin sister, becoming a primary threat in her life. Aware of this battle for control, the fading Aki writes a desperate letter to Aya, begging her to kill him if his past self completely takes over, demonstrating the depth of his original selfless nature even as he is consumed.

Aki's key relationships are defined by tragedy. His bond with his twin sister, Aya, is the story's most heartbreaking. The affection between them is corrupted by his transformation, turning him into her relentless pursuer. He also shares a significant relationship with Toya, a young man employed by the Mikage corporation. Toya sympathizes with Aki's plight and sees him as a responsibility, attempting to rescue him from the corporation's control. Despite his deteriorating state, Aki retains some degree of care for Toya. As a member of the Mikage family, he is also a tool of the corporation, which actively works to unlock the progenitor within him for its own purposes.

Aki's development is a tragic arc of losing one's self. He begins as a gentle boy but is progressively dominated by a violent ancestral spirit. However, his story does not end in complete surrender. He gradually begins to resist the progenitor's control from within. In the final confrontation, he manages to regain a degree of autonomy, using it to sacrifice his own life. He holds onto Ceres so that she can destroy him and the progenitor spirit, an act that saves Aya. In the aftermath, Aki is seen ascending with Ceres' guidance, and it is hinted that he is later reincarnated, finally free from the tragic cycle of the Mikage lineage.

Regarding notable abilities, Aki himself does not possess unique supernatural powers in his original state. His primary and most significant ability is to act as a medium or vessel for the spirit of the progenitor, Mikagi. Once this personality awakens, the progenitor possesses formidable power, being the one who originally trapped the celestial maiden Ceres on Earth. In this state, he becomes an incredibly powerful and dangerous adversary, but this power belongs to the ancestor, not Aki himself. His final act of sacrifice, a choice made through sheer will, becomes his most defining and heroic deed.