Driven by the pursuit of wealth and knowledge, Kiwi Araya, a young man who ran a clinic as a dark healer in the kingdom, is branded a heretic within the country after a war breaks out between the kingdom and the demon realm.

Threatened by the royal army with an inquisition and burning at the stake unless he closes his clinic and assists in torturing captured demons, Kiwi makes an immediate decision:

"In that case, I'll just defect."

Reasoning that he could no longer make money in the kingdom, he devises a plan to defect, choosing to work in the demon realm. Though entirely driven by self-interest, his honest and responsible work, combined with the demons' positive misunderstandings of him, allows Kiwi to steadily build trust and wealth in the demon realm.

Meanwhile,

"Um, the demons are charging without any fear of injury!?"

In the kingdom Kiwi abandoned, they are now being overwhelmed by the demon realm's soldiers, who inexplicably recover from injuries instantly. The war, once decisively in their favor, gradually begins to shift...?

※Novelization and comic adaptation decided! Project in progress!

※Also posted on Kakuyomu.