Manga by author Light Tuchihi

The story begins when the goddess Listarte summons a hero to help her hard mode video game-like world. The hero, Seiya, is exceptional in every way, but he is incredibly cautious. He does things like buy three sets of armor (one to wear, a spare, and a spare for the spare) and go full power against weak slimes (just in case). From ANN.

The goddess Lista summons a hero who excels in every area to assist her. He's everything she expected him to be except for one, tiny thing: this anxious hero can't do anything unless he's absolutely sure nothing can go wrong!