Inuyasha the Movie 4: Fire on the Mystic Island
犬夜叉 紅蓮の蓬莱島 (original)
Ai, a young half-demon who has escaped from Horai Island to try to help her people, returns with potential saviors InuYasha, Sesshomaru and Kikyo.
Starring Kappei Yamaguchi, Satsuki Yukino, Koji Tsujitani, Houko Kuwashima, Kumiko Watanabe, Noriko Hidaka, Fumiko Orikasa, Yu Kobayashi, Reiko Kiuchi, Yuki Masuda
It's a animation and action & adventure movie, and has a rating of 7.2 out of 10 from Imdb which is usually fine for this kind of movie.
Watch it here
Not found streaming from Singapore.