Kasuki a young Senior highschool boy was suddenly summoned to another world to be a hero.  However when his stats were evaluated they appeared as an error.  Even though he wanted to be teleported to a peaceful place, he wasn't granted that wish. His sister and best friends jumped into the circle with him.  Now they ended up in the Dungeons of Chaos fighting to survive and get revenge on those who cast them away after they interrupted their peaceful lives.