Rui

Rui (ルイ) is the Celestial Empress (天帝, Tentei) of the Celestial Empire in the second part of Hokuto no Ken. Elder twin sister of Rin, she lives imprisoned for nearly her entire existence by Jakoh, who uses her captivity to blackmail Falco and establish a reign of terror over the Empire. Representative of the Polar Star (天帝星, Tenteisei), she embodies the true spiritual authority that the warriors of Gento Kōken have sworn to protect.

Birth and separation from Rin

Rui is born within the imperial family alongside her twin sister Rin. According to an ancient law of the Gento Kōken, the heavens would be torn in two if two Empresses coexisted; Jakoh, a corrupt viceroy, therefore orders the execution of one of the two twins.

Falco, to whom this task falls, cannot bring himself to carry it out. He secretly entrusts the baby Rin to his own uncle and aunt, who will raise her as their own child. Rui, the elder twin, remains at the imperial palace and officially ascends to the throne as Tentei.

Captive of Jakoh

Fearing that the Empress might one day turn against him, Jakoh kidnaps Rui as a child and locks her away in the catacombs beneath the imperial palace. This captivity serves as a permanent blackmail weapon against Falco and the other masters of the Gento Kōken: as long as Jakoh keeps the Empress prisoner, their oath of allegiance compels them to obey the worst orders in order to preserve her life.

For years, Rui lives at the bottom of the stone well, deprived of light, digging through rock to reach a water vein. This existence in total darkness eventually causes her to lose her sight. Despite her isolation, she remains lucid and aware of her people's suffering. She has even heard of the exploits of a young resistance leader, without knowing that it is her own sister.

Meeting with Rin and Ein's sacrifice

When the Hokuto Army attacks the Imperial Capital, Bat, Rin and Ein infiltrate the palace to unmask the false Emperor. Trapped by Jakoh, they fall to the bottom of the well where Rui lives. It is in this darkness that the two twins meet for the first time, and Rui reveals to Rin the truth about their shared birth. Meanwhile, on the surface, Falco and Kenshiro clash in a duel that ultimately makes them realize that two Tentei exist.

Trapped in the well, Ein sacrifices himself by striking the rock to release the underground water vein, whose pressure propels the three survivors to the surface. Ein's sacrifice allows Rui to see the sky again after so many years, and allows Falco to turn his weapons against Jakoh, whom he strikes down without mercy.

Liberation and restoration of sight

Once Jakoh is dead and the reign of terror is over, Rui regains her sight and weeps with gratitude before Falco, fully realizing the extent of the sacrifices he made to protect her. The Imperial Capital is, however, destroyed shortly after by Jask, Jakoh's son, who triggers the detonator designed by Falco and kidnaps Rin to take her to the land of Shura.

Rui watches helplessly as this new separation unfolds. She laments the cruel fate inflicted upon the two sisters and the heavy burden that once again falls on Kenshiro, who has set out alone across the Sea of Death to save Rin.

The Empress of Polaris

Rui embodies the Tenteisei (天帝星), also called Taikyokusei (大極星) or Polaris, the fixed star around which all others revolve. This imperial star is not Hokuto, which refers to the Big Dipper, but the celestial pole itself, and it is in its name that the Gento Kōken protects the Empire and fights anything that might eclipse it.

Despite her physical frailty, her past blindness, and the absence of personal ambition, Rui remains a figure deeply respected by the inhabitants of the Empire. She represents spiritual legitimacy in the face of Jakoh's usurpation, and the peaceful end of a cycle of violence set in motion by the viceroy's reign. Rui appears in the final part of the original animated series (Hokuto no Ken 2, 1987-1988), during the Tentei arc, where she is voiced by Yoshino Takamori. Maaya Sakamoto takes over the role in the Shin Kyūseishu Densetsu trilogy.