"Street Fighter Alpha" is a manga adaptation of the popular fighting game series, focusing on the events that take place between the original "Street Fighter" and "Street Fighter II." The story primarily revolves around Ryu, a wandering martial artist, and his internal struggle with the Satsui no Hado, a dark and destructive force within him. Ryu's journey is intertwined with the lives of other fighters, each with their own motivations and challenges.

The narrative begins with Ryu encountering a young girl named Shun, who claims to be his sister. This revelation forces Ryu to confront his past and the mystery of his lineage. As Ryu delves deeper into his origins, he crosses paths with Ken Masters, his longtime friend and rival. Ken is drawn into the conflict as he seeks to support Ryu while also dealing with his own responsibilities and relationships.

The story introduces several key characters from the "Street Fighter" universe, including Chun-Li, an Interpol officer investigating the criminal organization Shadaloo. Chun-Li's quest for justice leads her to uncover the sinister experiments conducted by Shadaloo, particularly the creation of powerful warriors like Cammy, who struggles with her identity and purpose. The manga also explores the backstory of M. Bison, the leader of Shadaloo, and his relentless pursuit of power through the Psycho Drive, a device capable of amplifying psychic energy.

As the plot progresses, Ryu's battle with the Satsui no Hado intensifies, leading to a climactic confrontation with Akuma, a master of the same dark power. Akuma serves as both a mentor and a nemesis, pushing Ryu to the limits of his abilities and forcing him to choose between embracing the darkness or finding a path of balance and control. The manga also features Sagat, a former Muay Thai champion seeking redemption after his defeat by Ryu, and Dan Hibiki, a comedic yet determined fighter striving to prove himself.

Themes of rivalry, self-discovery, and the struggle between light and darkness are central to the narrative. The manga effectively captures the essence of the "Street Fighter" universe, blending intense martial arts action with character-driven drama. The interactions between the fighters, their personal growth, and the overarching conflict with Shadaloo create a cohesive and engaging storyline that appeals to fans of the franchise.