There's Definitely Something Wrong with the Young Lady's Personal Butler!

As an S-rank ace agent in MACA, a mysterious United Nations agency, he met with an accident during his final mission. But, astonishingly, after entering a chaotic space, he became a 16-year-old boy named Gao Ming, and at the same time a servant in a mansion. While trying to regain his strength, Gao Ming is also working to uncover the truth.