The book of lost things influenced 君たちはどう生きるか (The Boy and the Heron)

Studio Ghibli has said that John Connolly's novel was among Miyazaki's inspirations for The Boy and the Heron. Both follow a boy grieving his mother during the Second World War, resentful of the woman who has taken her place, who passes into another world and meets a sinister guide there.