One Piece: Unreal Adventure - Chapter 42: Join my pirate crew.

Sian Lee, the strongest person under the heavens in old china, was reborn as a very overweight woman.

I never thought I had meaning to my life, but I guess I have a talent too.

「Get ready. The duel will begin soon.」

God: I shall bestow the Saintess upon you.
Pope: W- wait a moment! This is a boy!
God: That is the Saintess.
Pope: ??????

And just like that, the Saintess was raised by the church for fifteen years without any questions asked…

- Description from Novelupdates

Razé was a cheat soldier at the age of 15, thanks to the memories of her previous life. One day, she was summoned by her superior – the devil Prime Minister and was ordered to go on a long-term solo mission. She was expecting a harsh mission, but…

“I knew you are the right person for this, Lieutenant Colonel Razé Orphan. I want you to attend the Centrior Imperial Magic Academy starting from this spring.”

“…..what?”

Well, it seems that she has been appointed as the “bodyguard” for the prince and other noble’s kids. And so, she was enrolled to the school where the aristocratic-sama gathered.

Although she was puzzled by the glittering school life, she was trying to live a life so as not to be bullied in the future. But it seems there was a secret that she didn’t know hidden in this world.

“Hey!!!!!! No one told me that this is an otome game!!!!!”

As a bodyguard, her life would be over if any of the noble kids got hurt. But then a young lady who claimed to be the ill-fated villainess came by. If the girl died, won’t she be dead too?

Today, Razé will continue to watch over her school life (with her own life on the line).