The story begins in the final years of the Meiji era, shortly after the Russo-Japanese War. With Japan's demand for electricity skyrocketing, a young engineer named Saeki Ryouji returns home from Europe to take on a pivotal project: the construction of a rural hydroelectric power plant. His days become a frantic rush of blueprints and planning, and always at his side is his loyal assistant, Edward.

Ryouji first encountered Edward two years prior, finding him working as what others dismissed as an idiot unable to speak. Taking pity on him, Ryouji took the young man under his wing, and a formal master-and-servant relationship was established. Edward, in turn, became an indispensable and devoted attendant. However, the nature of their bond is beginning to shift. As they labor together on the hydroelectric project, the quiet, unspoken emotions between them start to surface, transforming their strictly defined roles into something more intimate and complex.

The primary setting is the Japanese countryside during a period of rapid modernization, where traditional social structures clash with new Western technologies and ideas. The central conflict is internal and relational, revolving around the gradual, subtle change in the master-servant dynamic. Ryouji is a dedicated engineer caught up in the feverish pace of early industrial development, while Edward is a mysterious figure whose past is largely unknown, initially characterized by an inability to speak. The narrative arc follows their journey from a relationship of caretaker and charge to one of growing mutual affection, exploring how their deepening personal feelings challenge the rigid social hierarchy of the era. The limited series of nine chapters fully chronicles this slow-burning romance set against the backdrop of Japan's energetic push into the twentieth century.