Late Meiji Era. In response to an increasing demand for electricity after the Russo-Japanese War, Saeki Ryouji, having returned from Europe, takes on a project to build a rural hydroelectric power plant, and becomes inundated with work as the engineer. Beside him is his loyal assistant, Edward. Saeki had found him two years ago working as "an idiot unable to speak", and took him under his wing. Their relationship as master and servant, little by little, begins to change...