An adaptation from Manga. Directed by Michael Arias and animated by Studio 4°C.
Besides having a unique style to the characters, I love the fact that they use post production techniques like motion blur, handheld camera, glow and smoke effects to enhance the quality of the image. It is not common to see these in an anime film.
Another awesome thing to note is the use of a stop-motion in various scenes to exaggerate a mental state of the character. They include using color pencil drawings like that from a child, flowing paint and perhaps other traditional techniques.
You have to watch it to appreciate the aesthetics!