The Boy and the Beast is a journey between two different worlds. It begins in a monochromatic Shibuya district in Tokyo, where Ren a 9-year-old boy ran away from his relatives after his mother passed away.
After living on the streets and wondering lost in Tokyo, one night he sees Kamatetsu, a beast that looks like a bear and talks to him briefly and goes away. Ren decides to follow the Beast and that is when the boy discovers a mystical portal, he is transported to Jutengai. This place is populated by animals with humanoid aspects. There he meets Hyakushubo, a pig aspiring to be a monk; Tatara, a skeptical chimpanzee; and Kumatetsu, a temperamental bear who decides to train Ren in kendo or something that is very similar to kendo.
Of course there is an explanation of why he wants to train Ren in kendo, but if I say it I might give a huge spoiler. The director choises of actions during the fights, the humor sequences between Ren and Kumatetsu are the best attractions of this movie.
Besides all the characters' personalities being a lit bit cliché, as we see them growing in character and age we feel more connected to the whole story that to me was very moving.
This movie got a 90% of approval at the rotten tomatoes and I also recommend it to everybody.