A gruff beast and a street kid learning to need each other hits different when you realize it's actually about a parent choosing to stay. The animation doesn't just look beautiful, it moves like it understands loneliness and what it costs to let someone in. By the final act the story loses its footing, but by then you're already grieving a relationship you know can't last, and that's the entire point.

Ren is a nine-year-old orphan. The last person who showed him kindness has died, and what remains of his family shuns him, so he runs off into the backstreets of Shibuya. There he runs into Kumatetsu, a gruff warrior beast who brings him to Shibuten, the realm of beasts. Kumatetsu is nearly unbeatable in a fight, but his cold manner has left him without a single disciple, and he needs one to be considered as successor to the realm's retiring lord. The two strike a deal: Kumatetsu takes the boy, now called Kyuuta, as his apprentice, and Kyuuta gains a place to belong. They bicker constantly, yet as the years of training pass, they grow into something like father and son. When a deep darkness threatens to plunge both the human and beast worlds into chaos, their bond faces its hardest test, and they can only prevail by finally fighting side by side. The film is a fantasy adventure that mixes action, comedy and drama.