I don’t know what it means to be a literary author, but perhaps コンビニ人間 is a good pick. It’s among the easier books we’ve read in intermediate book club, while also being one of the more well-liked choices.
It can’t hurt to read at least one young adult book before moving on to more complex works. In which case, maybe you’d be interested in reading 魔女の宅急便 with a book club.