Ochikobore Shougakusei, Isekai & Gendai de Saikyou Yuusha to Naru

Synopsis

I will definitely become stronger to save my precious family! Toba Akito is an elementary school student who is not as good at sports, studying, or anything else. One day, due to his own carelessness, his beloved younger sister is in danger of death... At the moment he despairs at his own powerlessness, the goddess who designed the human race appears and tells him that she made him a "dropout" due to her mistake... However, the goddess takes him to another world where he can definitely become stronger through effort and experience--!? "I will become strong in the other world. And I will save my precious family!"