Movie
Description
Yusuke Ninomiya, known as Yu, survived an infant plane crash that killed his parents but left him paralyzed and permanently reliant on a wheelchair. Raised in a Tokyo hospital, he heard tales of magic and world-traveling from an elderly patient. Later adopted by a florist, he lived with adoptive sister Saki Mishima. As a child, he intervened when Haruto Ichihara provoked a dog; Yu lured the animal away by throwing a stone at himself, allowing both to escape and forging an enduring bond with Haruto.

In high school, Yu used his analytical mind to craft basketball strategies for star athlete Haruto. Both developed feelings for classmate Kotona Takashina, though Haruto ultimately dated her. Yu sometimes missed group activities due to inaccessible venues. When Kotona called in panic, Yu found her pursued; an attacker stabbed her with a mystical dagger just before Haruto arrived. Fleeing the scene, all three narrowly avoided a traffic collision and were transported to Ni no Kuni, a parallel fantasy world where Yu could walk.

Yu and Haruto encountered Princess Astrid of Evermore, who resembled Kotona and bore identical curse marks. Yu removed a manifested dagger from Astrid's chest, breaking her curse. He deduced Kotona's life in their original world was intrinsically linked to Astrid's existence. After Kotona was diagnosed with a terminal brain tumor, Haruto resolved to kill Astrid to save her. Yu opposed this, refusing to sacrifice Astrid despite the personal stakes. Captured in Ni no Kuni after another assassin encounter, Yu was forced to battle Haruto during the Black Banner army's invasion of Evermore. Their duel triggered a return to their original world.

Yu deduced Saki's life was linked to captured knight Bertha Roam. He and Haruto rescued Saki from the assassin, who transformed into a monster. Returning to Ni no Kuni, they exposed Crown Prince Sedulus Astrum as the true antagonist; he had manipulated events while disguised as minister Gnauss Wisden. In the final confrontation, Yu intercepted Sedulus's fatal attack aimed at Astrid, sustaining critical wounds. An elderly man revealed as Oliver from another timeline declared Yu a true hero. Empowered by the Divine Avnaron and sword Mornstar, Yu helped defeat Sedulus.

The resolution revealed Yu originated from Ni no Kuni, not the human world; his presence during Haruto's childhood was a temporary crossover to save Haruto from the dog attack. Post-battle, Yu chose to remain in Ni no Kuni as Prince of Evermore, entering a relationship with Astrid. Those in the human world forgot him, though Haruto retained their shared memories. Yu consistently demonstrated strategic thinking, loyalty, moral conviction, and protective instincts, contrasting Haruto's impulsiveness. His journey transformed him from a reserved student constrained by disability into a decisive leader embracing his true heritage.