One day when he was usually doing his shopping on a mail order site to search for a book to buy so he could read it while commuting. A book that had something like living a life in another world was put up for sale. The contents were very fascinating that

A man on his way home from work, he is playing a tower defense game of his smartphone. Then he notices a small girl who is about to be hit by a car. He jumps out in an attempt to save her life."Stupid" is the last word he heard before his death.

Senior High school student, Nagato Kazuya has received the ability to summon modern weapons and soldiers in another world. With a Yandere advisor and the soldiers that he summoned, he was now doing as he pleased in the skies, ground and seas of the othe

One day a man fell in a pothole on his way home. Before he noticed, he was in a strange room with a mysterious voice who claims to be [The system between worlds] proclaiming his death as well as stating "What you fell in was a hole to the lower world".