I've Truly Lived Long Enough

My new book is asking for your collection, votes, comments, and more! In short, I'm begging for everything! As usual, do you have any book recommendations?

I'll start a thread for the author as a minor character.

You all have no idea how hard the author worked. To write this book well, the author even went to a mental hospital to experience life there firsthand. Those chapters that seemed to be playing tricks on us were just the author having so much fun that they forgot about them.

They've borrowed so much from the abyss that they even borrow from deception. (Considering the author might say, "Plagiarism is impossible; how can you call it plagiarism when it's the author's work? It's just borrowing ideas," so...)

The second floor might be me, probably.

This adorable boy, aside from having one less hole than a girl, one more way to play, and being unable to get pregnant, what's the difference? Author, don't be shy, this is the female lead!

This author is cheeky, perhaps we should...

I have an idea: since the protagonist is immortal and nothing can affect him, could we add a parasitic creature to him, like tentacles, tentacles, tentacles, and more tentacles?

It seems like after falling into a deep sleep.

As the title suggests, I'm posting a search notice for a new book. A generous reward will be given if it is discovered.