Kafka on the Shore by Haruki Murakami

Kafka on the Shore, a tour de force of metaphysical reality, is powered by two remarkable characters: a teenage boy, Kafka Tamura, who runs away from home either to escape a gruesome oedipal prophecy or to search for his long-missing mother and sister; and an aging simpleton called Nakata, who never recovered from a wartime affliction and now is drawn toward Kafka for reasons that, like the most basic activities of daily life, he cannot fathom.