Don't Use Me Too Hard Master

Clear was just a normal boy once, had brothers, had a father, had everything he could ever ask for. Until he realized he was actually an android and forced to kill everyone he knew. An elder man who looked after him one day kidnapped him and ran off to live peacefully elsewhere. As he grew, he always heard a voice in his head. He never knew where it came from exactly, so, dawning his gas mask and umbrella, he wound the ways of the streets, trying to find the master of the voice.