"You have acquired experience points. Kazuto Kudou has risen to Level 1," echoes through Kazuto's mind after he runs over a mysterious dog on his way home from work. The next morning, he awakens to a changed world, full of vicious monsters. The world now features a game-like system of levels and skills, alongside danger at every turn. Will Kazuto be able to survive by leveling up and taking advantage of the special skill he acquired the previous night? His survival adventure begins now!