Cain has been named a baron and given a mansion—an old, dilapidated one. But with his magic, he's able to fix it up like new in no time, and he immediately starts preparing to host a debut party to introduce his mansion to noble society.

Cain finally reaches his twelfth birthday, the day he can register as an adventurer. He heads straight to the guild to sign up, but some older adventurers pick a fight with him, and he's saved by a red-haired man who looks very familiar...