Any recommendations, apart from the obvious like Mishima, Akutagawa and Soseki?

Reika Monogatari, The Manyoshu, the Tale of the Bamboo Cutter, and the Heike Monogatari are classics. If you don’t like traditional fiction then try Kobo Abe’s Woman In The Sand Dunes or Ryu Murakami’s In The Miso Soup.

I don’t know if you consider VNs and light novels to be lit but there’s those too.

Start with the kojiki

anything by Kenji Siratori is rather avant garde modern japanese literature