@Kanol
not possible. it cant be the same universe because its exactly the same as a game he played on earth. ship models, lore, armaments... he has advanced knowledge of all of it because he played the game.
@Capt_Gigglepants As far as we know, it's a world that has a lot of similarities to the game he played, but not everything is the same. There are ships and other things he hasn't seen.
If you want to go full tinfoil-hat mode its actually possible, but extremely unlikely.
The game could just have been made by some super-intelligence to simulate the universe.
You could even make an argument that the "updates" were only implemented after said super-intelligence made simulations predicting the future.
( who knows, when you are at that level you might find it funny to just fuck with a random bumfuck on a backwater planet just to see what happends. )
At the end of the day if you know the position of every molecule in the universe you could make a program that predicted the future by running simulations at a higher speed.
But again, that's going super hard on the tin foil and while possible is super unlikely to the point that even his own explanation of coming from a different universe/dimension is more likelly.
Man, in the novel it just said that Mimi is a fan of "gothic lolita" so I completely forgot that gothic lolita isn't just black frilly dresses but lots of cute frilly dresses. THANK YOU MANGA!