Aaaaaand... I'm sticking to my original theory.
The main character has played Eternum before and the whole game, even the school life, is all still the game. He wipes his memory before going in, so he can't just use the same old tricks to win. He's beat it so much he had to wipe his memory just for a challenge. This new update SCREAMS at me that my theory is sound.
Problem is, I bet he doesn't see that the game has become an addiction. For him and the other playing it. In the end, he will have to shut down the game. And that's GAME OVER. No harem ending. Simply because, that would be wrong. Those are all characters. In the end, you turn off the game, and go live a real life. And free all those addicted to the game from your own creation. Your own beautiful Hell.