Hikaru no Go centers on Hikaru Shindo, a young boy who discovers an old Go board haunted by the spirit of Fujiwara no Sai, a Heian-era Go master. Initially uninterested in the ancient board game, Hikaru reluctantly begins playing Go under Sai's guidance. As Sai's passion for the game influences him, Hikaru gradually develops his own interest and skill in Go, transitioning from a novice to a competitive player.

The narrative follows Hikaru's journey as he navigates the world of competitive Go, starting with casual games against classmates and progressing to professional tournaments. His growth is marked by encounters with skilled opponents, most notably Akira Toya, a prodigious Go player and the son of a renowned Go master. Akira becomes Hikaru's rival and driving force, pushing him to improve and challenge the boundaries of his abilities. The rivalry between Hikaru and Akira forms a central dynamic, showcasing their mutual respect and determination to surpass one another.

Sai's presence serves as both a mentor and a source of internal conflict for Hikaru. While Sai's expertise elevates Hikaru's gameplay, the boy struggles with the ethical implications of relying on Sai's skills. This tension culminates in Hikaru's decision to forge his own path, striving to become a player who can stand on his own merit. Sai's eventual departure marks a turning point, forcing Hikaru to confront his dependence and redefine his relationship with the game.

The series explores themes of perseverance, self-discovery, and the pursuit of mastery, set against the backdrop of the intricate and strategic world of Go. Supporting characters, such as Hikaru's friends and fellow players, contribute to the richness of the narrative, highlighting the communal and competitive aspects of the game. Through tournaments, training, and personal challenges, Hikaru evolves from a reluctant participant to a dedicated and passionate Go player, leaving a lasting impact on those around him.