Ah the Superman origin, just take your name from the sleep clothes you brought from your home world, makes sense. Also better than the other isekai stories, where the guy gives himself a chuuni name, and then whinges about how embarrassing it is.
And he couldn't choose a worse name? Then again his naming sense is amongst the worst I've ever seen. At least gol-tarou became Gretel which is orders of magnitude better.