The most obvious feature of this film is the beautiful art. This point doesn't need to be expanded upon. Any description will fail to convey the charm of the beauty of every scene of the movie. All of the backgrounds are detailed and full of life. This gives the film a very real feel.
What plays a much more important role in the realism are the characters. Those featured in this film are few but well thought out. The main character acts in a lot of ways like a real person. The creators have included very subtle gestures using the eyes, face and hands to truly bring Anna to life. Her behaviour is very realistic for a child of her age. I personally could put myself in her shoes. Awkward moments felt truly awkward, and I instantly remembered the moments when I acted the same way as Anna.
The character of Marnie was purposefully left a little bit mysterious and unreal, to reflect the fact that she was in fact a memory. The atmosphere changes significantly whenever she's on screen. This was achieved using music, clever cinematographic play, and art. All of those had been well thought out to create a mysterious dreamy feeling of uncertainty as to who Marnie truly is. The memories of her slowly come together to form a coherent whole, and we truly understand this person.
The supporting cast is more or less left intentionally blank. However lacking in detail they might be, the entire cast is composed of characters one might find within one's own acquaintances and family. They all seem very real, and this is achieved using a minimum of dialogue and gestures. The random children from preschool act and sound exactly how one would expect them to, as do the teenagers, parents, and random people from the village.
Most of the cast is female. This is perhaps an overlooked, but important fact that should be pointed out.
The music and sound effects don't stand out too much, but that is for the better. Nowhere in the film does the music or the art overwhelm what's most important: what are the characters saying, doing, and feeling. The sound and graphic design is so detailed and subtle, that it allows to immerse yourself in the world of this story.
All in all, the film feels extremely real and subtle. It's not trying to overwhelm you with emotions and flashing CGI. It charms the viewer by showing a world which feels more real than our own.
