Author, life is hard atm hu
? And we can feel it with how much it's overcooked.
More likely it's a trap to brainwash him. But ok, let's get along with the "Shigoku is your best friend" and your memory it's fabricated. Let's try to overcook like the author.
So, with this weird idea, the truth is our mc is trapped in a nightmarish virtual world, since chapter 1, after trying a machine to heal his past trauma with advanced VR AI. But his negative thought are so strong and in result, he has polluted the system and twisted his own memories, make him believe that this revenge story is real.
And Kyou he's really his best friend send in by the admin to save him. And this shit will reactivate his true memory and enable the logout.
Welp, for me it's the only headcanon which will make me accept that the mc think is a good idea to use this machine (wth, this shit look so sleek and costly).