Touya is reborn into another world when the god mistakenly killed him. He requested to bring his smartphone into the another world, so the god made a few modification to it to make it possible 

God also greatly amplifies Touya's physical, magical, and cognitive abilities to a certain degree as a further apology for the inconvenience of killing him.

<3 

Watch this is you want an anime with less problems or drama. Its amazing how touya achieve things easily, even having multiple wives haha