What a great art... It's simple and soft, pleasing to the eye, while the action shots are expressive and powerful. Awesome artist.
The story's tone is really good, so far. It's nice that author gave us some mysteries to think about right off the bat too. There's nothing more boring than a smooth and simple start in an isekai. One must give at least one good plot hook early on, even if it gets explored only much later. Mystery is a must for this genre.
A strong start for sure. Even implied future harem (which is a cancer eating many decent stories from inside) doesn't ruin it for me.