Japanese literature–manga aside–has been a huge impact on me and I hope it’ll be for you as well.
So here’s one of Japan’s most prominent writers and one of my favourites. :)

As far as I know, these are the ones available digitally. Let me know if there’s something I missed out on.

Note:

No Longer Human & A Shameful Life are both Ningen Shikkaku.

No Longer Human - translated by Donald Keene (1958) [New Directions Publishing]
A Shameful Life - translated by Mark Gibeau (2018 - new translation) [Stone Bridge Press]

Let me know if there are problems with the files :)