Even young adult novels often have at least some illustrations, but it is rare in adult fiction. ... The probable reason is that children demand illustrations in their books, but adults are perfectly content to read pure text. In other words, it's market-driven.Aug 19, 2019
Do high school DxD light novels have illustrations?
High School DxD is a light novel series written by Ichiei Ishibumi and illustrated by Miyama-Zero. It has been published in Dragon Magazine since September 20, 2008 under the Fujimi Fantasia Bunko imprint.