Activating a Portal to Trade Between Two Worlds: A Fortune-Making Legend

[Transmigration to another world, cross-plane trade, making money, daily life, multiple races and heroines, no romantic misunderstandings, mind the traffic]

A mysterious portal opens the secret to wealth in two worlds!

I use knowledge and technology from another world to trade for anything here.

I “save” noble girls in trouble, “shelter” hunted demi-human girls, and “fund” a princess with nowhere else to turn.

They see me as their savior and willingly gather under my banner.

They don't know I'm selling more than goods. I'm bringing an entire set of rules that will turn the world upside down.