Hideo Masa was poisoned by people he annoyed on a regular basis. Why would he annoy them, because he didn't like them? Since he considered himself the protagonist, he was therefore the good guy. As the good guy, his enemies were the villains.

So as he drifted off into deaths embrace, he was offered a contract by a god from another world. He would accept death, or be reborn as the destined savior of the planet. Like any normal human being, he chose to be one of the reincarnated people he read so much about.

Upon, arriving to his new world, Hideo renamed himself ""Protagonist"" and set out to ""save"" the world. In the end he succeeded, or at least he thought he did. He eliminated most crime and corruption and mostly everyone was well-fed and happy... incidentally, while saving the world, he also unwittingly re-made it in his image thus angering the god who brought him there.

So he was ""made to lose consciousness"" and launched into space. However, the story does not end there. For the many blessings he received kept him alive as he floated through the void in a state of unconsciousness. He was eventually found by another god and thrown onto the planet it inhabited. Then given contract not to save the world, but to live life as he pleased.