My immediate pick is 'ingenuous'—it has that quiet, layered quality literary fiction loves. To me, 'ingenuous' suggests more than simple cluelessness: it implies sincerity, a lack of guile, and a worldview that can be both disarming and painfully honest. In novels that dig into inner life, calling a character 'ingenuous' lets an author explore moral complexity without turning the character into a caricature. It reads like an invitation to empathize rather than to mock.
When I read stories where the narrator or protagonist is learning, misstepping, or seeing the world through an unfiltered lens, 'ingenuous' preserves dignity. Compare that to words like 'obtuse' or 'benighted'—those feel harsher and flatten the character into a target. 'Naive' is close, but can sometimes sound judgmental; 'ingenuous' keeps a softer, more interpretive tone, which is why I tend to favor it. I find it opens up scenes to subtle irony and emotional resonance, which is exactly what I want from great literary fiction.