Capital D, lowercase W, all one word as opposed to the real world, all lowercase, two words, which is where you're from and where I am from in this world, no one else.
〈現実世界とは 異なる場所なんだ〉 〈君と僕は―〉 〈ドラマの世界に来た 旅人だと思ってよ〉