One Piece: New Order - Chapter 57: The Battle of Sgri (Prologue)

She was used by her boyfriend to trap someone. Unexpectedly, things did not go as planned.

There was once a hero.

Unique black hair. Excellent eyes. Contrary to his delicate features, he who had abnormal strength was called the Otherworldy Hero.

At the hero’s long adventure (up to the point where his wooden sword that had been kindly granted to him by the king was replaced by the holy sword blessed by the holy maiden) he saved the prince that had been kidnapped by the demon king, and so the kingdom was swept by worry.

The hero’s strength that could fell the demon king was deemed too dangerous to leave unrestrained.

One advisor spoke up. Why not marry him to royalty?

The king thought that was a viable option. Family, to an alien from another world would be the best of chains. There was one problem. The king was abundantly blessed with sons and had princes galore, but not a single daughter.

Ho, and it wasn’t like I could marry off two boys.

At a burst of inspiration the king slapped his knee.

That was it!

You just had to turn a prince into a princess!

And so the hero ended up in a position to be marrying a man.

This story, is a tale of the aforementioned otherworldly hero, and his bride, the former-prince-now-princess and their ridiculously hilarious marriage.

Before the rebirth, Gu Qingyao wanted to marry him but did not dare to marry. After the rebirth, Gu Qingyao, with the space materials in hand, all day planning to marry him with a huge dowry.

“Missus, time to fulfil your duties!” Mu Yuchen demanded as he pulled Xi Xiaye closer with his arms intimately wrapped around her waist.

It was a meticulously planned feast for the powerful. Her fiancé had knelt down on one knee and proposed to her sister instead. Robbed of her right to her inheritance, she was prepared for the Xi family to throw her to the wolves.
As she slipped away from her family that had turned their backs on her, she found him — Mu Yuchen, the low-profile and reserved noble that ruled City Z and led Glory World Corporation.

“Mu Yuchen, let’s get married!” He looked up at her, then suddenly stood up.

“Where are you going?”

“Let’s go. Any later and the civil affairs bureau will be closed.”

- Description from Novelupdates