My Beautiful Nemesis Wife Turned Into a Magical Girl?

Treasure Trove, a fairly well-known black-market gear dealer in the Lower District.

His daily routine goes like this:

Leave home, get caught up in an incident, run into the magical girl Stardust, get chased and beaten, burn money to escape, go home.

It's so precise, you'd think he was cursed.

To escape this vicious cycle, he spent everything he had building a "magic interference device." The plan was simple: temporarily stop the magical girl who was always picking on him from using magic, then get his revenge by giving her a thorough beating.

But reality had other plans.

The device was overwhelmed by her out-of-control magic. A flash of white later, he had changed from an eighteen-year-old man into a fourteen-year-old black-haired beauty. Permanently. Before he could even figure out what had happened, his nemesis recognized him on the spot and carried him home.

"You're staying here until you've confessed all your crimes. I'll keep you under surveillance twenty-four hours a day."

"I'm your enemy, you know!"

"So what?"

"You're supposed to be a hero! Aren't you meant to deal with criminals when you find them?"

"..."

She looked at his face, then silently turned her gaze away.

"Quit talking and eat your food."

"A nemesis is supposed to act like a nemesis, damn it!"

"When are you going to admit that you actually enjoy staying at my place?"

"The day I blow up your house."

"Oh. Then turn down the heat in the kitchen first. The eggs are about to burn."