Tokugawa Ieyasu, the legendary founder of the Edo Shogunate, is supposed to be resting peacefully as a deity enshrined at Nikkō Tōshōgū. Instead, he finds himself abruptly reincarnated into the modern Reiwa era of Japan for reasons he cannot quite comprehend. Far from being a grand political drama, his new existence is a bewildering journey into a world of smartphones, vending machines, and high school girls.

The protagonist is Ieyasu himself, a master strategist and supreme ruler of the Warring States period, now forced to navigate the mundane yet utterly alien landscape of 21st-century life. The central narrative focus revolves around the comedic contrast between his ruthless Sengoku-era mindset and the peaceful, low-stakes conflicts of contemporary society. While the initial premise highlights his interactions with a group of modern high school girls, the core of his journey is learning to appreciate a "slow life" devoid of battlefield pressure.

The series primarily unfolds in a typical modern Japanese city, a setting that provides endless culture shock for the former shogun. Ieyasu leverages his historical skills for everyday tasks, often causing unintended commotion as his ingenious but outdated strategies clash with modern convenience. The manga establishes a notable narrative arc centered on Ieyasu's transition from a revered war god to a laid-back resident of the Reiwa era. Each chapter or volume explores a new facet of contemporary life through his eyes, transforming ordinary experiences into extraordinary adventures as the Edo Shogunate's founder learns to finally enjoy a peaceful retirement.