ZipperDemon

In a world where humans and demons work together, the protagonist, Yuma, has always lived a stifled, insignificant life, as if he would never see the light. Then, during a demon attack, he loses his mother and younger sister Yuna, and makes a contract with the Zipper Demon. From that moment on, with zippers as his blade, he vows to carve a ray of light through this gray world.