I Sell Bottled Water for Gold in Another World! Novel

College graduate Alex Carter stumbles upon an extraordinary discovery: his security guard uniform serves as a portal to a famine-stricken past where basic necessities are worth their weight in gold. In this desperate era, a simple bottle of modern mineral water commands payment in precious metals, while a couple of instant meals can purchase an oiran's companionship. Exploiting this temporal gateway, Alex shuttles between eras, trading everyday items from the present for extraordinary wealth and influence in the past. His modest transactions accumulate into vast fortunes and considerable power across both timelines. With such advantages at his disposal, dominating the modern world's economy within a year seems perfectly achievable. Meanwhile, in the ancient past, unifying an entire empire in just two years appears equally attainable. For someone with access to two worlds, such ambitious goals are simply par for the course.