Finn, a young man from a remote mountain village, used to be an administrator at a major adventurer's guild, but his incompetent boss and colleagues expelled him, calling him "useless!"

Lamenting his own perceived inadequacy, Finn, for the sake of survival, found re-employment at a small, struggling guild on the verge of bankruptcy.

However, no one at his former workplace knew the truth.

The truth was that Finn was a "Celestial Emperor-class" support magic-user raised by a demon lord, and had secretly been making his former guild prosperous.

High-ranking adventurers who knew of his competence began to gather around him.

Even as he said, "We're a small guild, so we can only offer beginner quests," he accepted them, and through word-of-mouth, his clientele steadily grew, leading to prosperity.

This is the story of a helpful young man who assists troubled adventurers, princesses in distress, and nobles, gaining their recognition, and runs his guild with his extraordinary support magic. Meanwhile, the incompetent major guild that expelled him declines.

[Book version currently available from Earth Star Novel] [Manga adaptation, all 3 volumes currently available from Kadokawa]