The King of Fighters is a tournament held in an alternate dimension, where contestants step into the competition through a secret Bluetooth headset that opens a gateway between worlds. In Boston, Mai Shiranui, [Maggie Q], and her boyfriend Iori Yagami, [Will Yun Lee], attend a private unveiling of three ancient relics—the Kagura Mirror, the Yagami Necklace, and the Kusanagi Sword. Before the crowd can process what they’re seeing, the notorious Rugal Bernstein, [Ray Park], storms the exhibit, steals the relics, and slips into a dimensional portal to wake the formidable Orochi, a legendary force said to grant almost limitless power. The reveal that the sword on display is a counterfeit throws the quest into disarray, and Mai is told—by an injured Chizuru Kagura, [Françoise Yip]—that the true Kusanagi Sword lies with Saisyu Kusanagi, [Hiro Kanagawa], inside a mental institution. Chizuru warns that Iori should stay out of the mission if they’re to have any hope of stopping Rugal.
At the hospital, Mai seeks answers and encounters a catatonic Saisyu; his son Kyo Kusanagi, [Sean Faris], is present, and when Iori’s inauspicious arrival stirs the elder Kusanagi back to consciousness, the aging warrior lashes out with a threat of violence before collapsing again. Meanwhile, in another hospital, Chizuru learns from her ally Scott that Rugal has tampered with the King of Fighters database, issuing challenges to fighters across multiple dimensions. Into this tangled web walks CIA operative and fighter Terry Bogard, [David Leitch], who confronts Chizuru, demanding the whereabouts of the relics. She explains the existence of parallel dimensions but urges him to seek answers in Seattle by consulting Mai, who has spent the past year undercover infiltrating Chizuru’s circle.
In Seattle’s cemetery where Saisyu rests, Kyo and Iori face each other and exchange uneasy truths: the Kusanagi and Yagami clans are destined rivals, a feud that has shaped their families for generations. Mai, riding with Kyo toward his home, discloses that she’s chasing the Kusanagi Sword as part of a larger plan to thwart Rugal. Kyo recounts ancient history—how a Yagami ancestor once attempted to unlock Orochi, but the beast consumed its host’s rage and surged into the world. In response, Kyo vows to confront Rugal, who has already driven his father into a shattered mental state.
The band of four—Mai, Kyo, Iori, and Terry—reconvenes at a hotel, where Rugal uses the tournament dimension to bleed into the real world. When Mai loses her cover in front of Kyo, Iori accepts the headset and dives back into the dimension to challenge Rugal. Inside, the heroes dispatch Rugal’s henchmen, Mature and Vice, but Iori’s mind succumbs to the Orochi’s influence, complicating their mission. The next day, Kyo is lured into the same battlefield, where he fights Rugal and loses, yet survives as a warning to others. He summons the ancestral sword again and joins Chizuru and Terry into the tournament, while Mai is dragged into the fray by Rugal.
Once united, the four are scattered across different dimensions. Kyo battles Rugal, while Mai and Terry confront Mature and Vice. As Rugal’s might grows, he nearly decapitates Kyo; at the crucial moment, Iori intervenes. Rugal then discloses a history-long grudge: years earlier, he fought Saisyu, Chizuru, and Iori over control of Orochi. In a brutal memory, Iori allowed Orochi to possess him, defeating Rugal but shattering Saisyu’s mind in the process. A fierce clash between Kyo and Iori ensues, culminating in Kyo slashing Iori and freeing Orochi from his body.
Weary but not defeated, Rugal pushes the trio into one more dimension, revealing his true plan: unleash full power in a final confrontation. Chizuru, appearing in multiple clones, reveals that she has located both the mirror and the necklace, but the first attempt to combine the relics collapses with Chizuru mortally wounded. Mai steps in as the mirror holder, and the trio presses Rugal, only to be overwhelmed once again by his overwhelming force. In a last act of defiance, Kyo’s sword is destroyed, but he conjures a brand-new blade to block a fatal fireball and, with a final throw, shatters Rugal.
Back in the real world, Scott lights a lantern on the ocean in memory of Chizuru. Kyo chooses to carry the family legacy forward, preparing to continue the tournament in honor of his father’s teachings, while Iori lingers on the pier, a silent witness to the cost of their shared battles. The King of Fighters saga closes on a note of resolve and continuity, as the survivors recommit to protecting the realms from danger, and the city of Seattle holds its quiet vigil for those who were lost along the way.
