InuYasha Movie 4: Fire on the Mystic Island
Plot Summary: The island of Hourai, controlled by four demon gods. A girl who knows Inuyasha appears: "Ai." Unchanged for fifty years, what is this girl's secret? When the cursed seal comes to the surface, it begins Inuyasha and Sesshoumaru's newest battle!
Other name: InuYasha: Guren no Houraijima, 犬夜叉 紅蓮の蓬莱島