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.
Kono Yuusha Ga Ore Tueee Kuse Ni Shinchou Sugiru
Synopsis Kono Yuusha Ga Ore Tueee Kuse Ni Shinchou Sugiru
Alternative Kono Yuusha ga Ore Tsueee Kuse ni Shinchou Sugiru; The Hero Is Invincible but Too Cautious; The Hero is Overpowered but Overly Cautious, This Hero is Invincible but
Author Light Tuchihi