1. Magical Realism
In a Murakami book anything is possible. Fish can fall from the sky, old men can talk to cats, paintings can come alive, and elephants are made in factories. With the exception of Norwegian Wood, his most grounded work, Murakami is best known for the fantastical and magical elements that crop up in his work. This is known as 'magical realism'.
Unlike in pure fantasy novels, however, the magical elements in Murakami's books don't offer any means of help to his characters, but rather give them yet another problem to deal with. Whether it's an old bell that rings by itself or entering a parallel reality, these fantastical elements are ultimately accepted as reality by these characters and as something they must deal with.
Magical realism is arguably the main hallmark of Murakami's work as both a stylistic storytelling device and his main tool for exploring the majority of the common themes mentioned in this list. Without the surreal aspects introduced through magical realism, his mundane characters couldn't embark on their surreal adventures. And without this, his examinations of individualism and identity just wouldn't be the same.
In other words, Haruki Murakami's writing just wouldn't be Murakami without magical realism.