The Boy and the Beast (2015)

Nine-year-old Ren finds himself living on the streets of Tokyo after his mother dies. He ekes out an existence stealing food and sleeping in alleys. One day he stumbles upon Kumatetsu, a warrior from the Beast Kingdom. He came to the human realm to find an apprentice. He selects Ren and brings him to the Beast Kingdom. Ren and Kumatetsu bicker and clash at first, but Ren eventually masters the combat skills of his teacher. After eight years, he becomes a highly-skilled fighter. Now Ren and Kumatetsu must face forces of deep darkness to save humanity and the Beast Kingdom.

The Boy and the Beast is an action movie featuring Koji Yakusho and directed by Mamoru Hosoda.

The Boy and the Beast is currently streaming on Crunchyroll Amazon Channel.

It is also possible to buy The Boy and the Beast on Apple TV.