Shindo Hikaru, an ordinary sixth-grader, discovers an old Go board in his grandfather’s attic. Stained with blood only he can notice, the board houses the spirit of Fujiwara no Sai, a master Go player from the Heian period who was
driven to suicide. Sai’s lingering soul yearns for only one thing: to play the "Hand of God," a legendary, perfect Go move. Bound to Hikaru, Sai convinces the reluctant boy to act as his physical vessel during matches.Initially, Hikaru plays Go solely as a conduit for Sai. However, this dynamic shifts abruptly when Hikaru faces Toya Akira, a brilliant prodigy of his own age burdened by expectations as the son of the reigning Go master. Infuriated by Sai’s overwhelming brilliance, Akira becomes obsessed with defeating Hikaru, unwittingly igniting a deep, burning passion within Hikaru to learn the game for himself. Driven by a newfound desire to stand on his own merits, Hikaru begins studying Go independently, eventually joining the Haze Middle School Go Club and stepping out from beneath Sai’s shadow.As the narrative progresses, the boys grow as rivals and peers. Hikaru enters the grueling Insei program to become a professional, enduring humiliating defeats, intense
psychological pressure, and the grueling demands of tournament play. Meanwhile, Akira achieves professional status early, watching Hikaru’s unorthodox, chaotic style with a mixture of frustration and intense respect. Their parallel journeys form the emotional core of the series, pushing both toward the pinnacle of the Go world while navigating the shifting sands of their unique friendship.Tragedy strikes when Sai realizes the cruel irony of their bond: he was only brought back to the mortal plane so Hikaru could witness and absorb his centuries of wisdom, paving the way for the future generation. Believing his time has run out, Sai vanishes abruptly, leaving Hikaru devastated and wracked with guilt. Believing he is the direct cause of Sai’s disappearance, Hikaru abandons Go entirely, refusing to touch the board.Friends and former rivals rally to pull Hikaru out of his despair. Through playing matches against formidable opponents, Hikaru begins to see Sai’s familiar strategies and presence reflected in his own stone placements. He realizes Sai’s soul is not truly gone, but lives on eternally within the flow of every game he plays. Reinvigorated, Hikaru returns to the professional circuit with a fierce, mature resolve. He dedicates himself to bridging the gap between ancient Go history and the modern era, determined to carry Sai’s legacy forward while forging his own definitive path as a master Go player.