In the present, Izuna Hatsuse and Tet sit down for a game of chess, wagering food as the stakes, and as the pieces shift on the board, Tet begins to unfold a long tale about how the world arrived at its current state. The story opens 6,000 years in the past, during the Great War, a planet-spanning clash where the sentient races contend for dominance as the powerful Old Deus strives to control the Suniaster—an elusive conceptual device that only reveals itself to the strongest being and would crown that winner as the One True God. In this brutal conflict, the world is torn apart, and humankind—the race unable to wield the planet’s magic—teeters on the edge of extinction. The human colony, led by Riku Dola and his sister Couronne, suffers devastating losses: a companion dies in a Demonia attack, the burden of guilt hangs heavy on Riku’s shoulders, and nightmares plague him as the battles close in around them.
While exploring a ruined Elvish hideout the next day, Riku discovers an Ex-Machina severed from its hive-mind because it cannot compute the human heart—the very idea that defies pure machine logic. Though hesitant at first, he is drawn to her when she challenges him to a game, and he accepts. Her formidable logic is recognized, and they form a fragile alliance: she stays with him to learn what it means to feel, to hope, and to fear. The Ex-Machina receives a name that signals both color and identity—Schwi Dola—and together the unusual pair begins to untangle the riddle of human emotion.
As their bond deepens, Schrvi/Schwi helps Riku face the tally of lives torn apart by the war, forcing him to reckon with his own past while sharing in her growing understanding of humanity. The two discover they make an extraordinary team, their strengths complementing one another as they hatch a plan to tilt the balance of power among the war-torn races. By tapping into the collective spirit-energy of every race’s circuitry and using Shuvi’s machinery to redirect it, they plot to pierce into the planet’s core and seize the Suniaster for themselves.
Riku goes so far as to propose to Shuvi, embracing love across impossible boundaries, even as the world around them trembles with conflict. The plan takes a brutal turn when it begins to threaten Shuvi’s own existence, and she decides to venture into the Suniaster’s heart to save him. Along the way she crosses paths with Jibril, and a fierce battle erupts. Shuvi is grievously damaged, but with the last of her strength she reunites with the Ex-Machina hive-mind and calls upon their power to aid Riku. In a final act of sacrifice, Shuvi shields Riku’s wedding ring as her body is destroyed.
Moved by Shuvi’s sacrifice, Riku completes the daring plan as the disparate forces of the world and the Old Deus assemble for a last, decisive clash. When weapon-fire tears into the planet’s core, the Suniaster finally reveals itself to him, but his arm dissolves as he reaches for it—the Suniaster rejecting him. In a quiet prayer to a God of Games—the same playful spirit he cherished in childhood—Riku pleads for someone to take the Suniaster and end the war. Tet, emerging from the depths of Riku’s imagination, grants that wish, seizing the Suniaster and using it to become the One True God who remakes the world with games as the rule rather than war.
Returning to the present, Izuna senses striking parallels between Shuvi and Riku, and between Shiro and Sora, hinting at reincarnations across time. A direct descendant of Couronne, Stephanie, keeps a necklace that belonged to Corounne and bears the names of Riku and Shuvi—names the two themselves scratched onto its surface. With those discoveries, the two look forward to a future where the game begins anew, ready to play again.
