Akito Soma is the sole child of former Soma family head Akira Soma and household maid Ren Soma. Before birth, the spirit of the Chinese Zodiac God possessed Akito, appearing in Zodiac members' dreams to foretell their meeting. Fearing replacement in Akira's affections, Ren demanded Akito be raised male under threat of abortion. Consequently, Akito presented as male throughout childhood, with only eldest Zodiac members Hatori, Shigure, Ayame, and Kureno aware of the true gender due to their shared conception dream.

Akira doted on Akito, reinforcing the belief that being the Zodiac God made Akito inherently "special" and deserving of the Zodiacs' unconditional love. Conversely, Ren inflicted psychological abuse, instilling deep-seated insecurities about being unwanted. After Akira's early death, Ren declared his affection mere amusement and Akito purposeless without him. This trauma, compounded by enabling retainers and absent moral guidance, fractured Akito's mental stability. A maid exacerbated this by giving Akito an empty box claimed to contain Akira's spirit—an object clung to for years despite doubts.

As Soma family head and Zodiac God, Akito wielded absolute authority, enforcing loyalty through fear and manipulation. Physically frail but emotionally volatile, Akito exhibited extreme mood swings between detached composure and violent outbursts. Crippling abandonment fears and a warped sense of entitlement from Akira's teachings defined Akito's core personality. Akito demanded exclusive devotion from male Zodiac members, viewing external relationships as betrayal. This bred severe misogyny, projecting hatred of Ren onto other women and punishing those perceived as "stealing" affection: throwing Rin Soma from a window for dating Hatsuharu, brutally beating Kisa Soma after Hiro's love confession, and blinding Hatori while blaming Kana for his marriage desire. Akito justified these acts by claiming divine privilege—a God could not be punished for controlling subjects' souls.

A bet with Ren intensified Akito's cruelty. Ren predicted the Zodiacs would abandon Akito, leading to a wager: if Akito permitted outside bonds and the Zodiacs still returned, Ren would concede; otherwise, Akito would leave the family. Confident of victory, Akito allowed Shigure's request to host Tohru Honda, believing the "outside world's cruelty" would force the Zodiacs' return. Instead, Tohru's empathy weakened the curse, fueling Akito's obsession with destroying her influence.

Akito's downfall commenced as the curse fractured. Momiji's sudden freedom after Kureno's earlier broken bond triggered a mental collapse. Akito stabbed Kureno in rage and attempted to murder Tohru, culminating in a cliff fall that hospitalized both. During recovery, Tohru—understanding Akito's isolation and parental trauma—offered friendship. This pivotal encounter led Akito to realize the curse was a prison of mutual pain and clinging to it perpetuated suffering. Akito decisively released the Zodiacs from their bonds, destroyed the Cat's confinement chamber, publicly revealed the female identity, and began living openly as a woman.

Post-curse, Akito sought redemption through practical atonement. Though Zodiac members like Rin withheld forgiveness, Akito accepted this as deserved. Ren continued hostilities, but Akito offered reconciliation, which was rejected. Akito married Shigure Soma, acknowledging their longstanding complex love, and gave birth to a son, Shiki Soma.

In the sequel era, Akito's transformation deepened. As a mother, Akito prioritized Shiki's freedom and emotional well-being, actively encouraging friendships and experiences forbidden under the curse. When Ren attacked Shiki with a knife, Akito shielded him and took the injury. Despite this protective love, Akito maintained distance from most Soma gatherings, viewing past actions' consequences as a personal burden. Self-forgiveness remained elusive; Akito felt undeserving of reconciliation and expected no absolution. Outside the family, Akito formed meaningful friendships with Saki Hanajima and Mine Kuramae, signaling a newfound ability to build healthy connections. Professionally, Akito continued managing Soma affairs but reformed oppressive traditions toward support over control. Physical appearance evolved: initially androgynous with short hair and male attire, Akito later adopted feminine clothing and shoulder-length hair, eventually wearing dresses with shorter hair in maturity. The arc spans tormented abuser to introspective protector, defined by overcoming inherited trauma and redefining identity beyond divinity and familial tyranny.