Shinigami in the Ninja World - Chapter 256: Royal Guard, Meeting the Soul King?

When a glorious old civilization was toppled overnight, a strange purple moon rose and thus began the Purple Moon Era.

A seafood chef inexplicably transmigrated into ancient times. Even though he landed in a family with a nobility rank, and theoretically was supposed to be rich, the most valuable thing in the house is a grey donkey…
Su Yu stared at the sky helplessly; in order to support the family, he could only take up his old profession and go out to sell fish.
Unfortunately, the royal family selected concubines from both genders. Even as a poor noble, he had no choice but to attend…
DISCUSSION TOPIC: Will I be selected if I display my fish-slaughtering skills?
“Meow!” His Imperial Majesty shook his tail.

- Description from Novelupdates

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.

He, without doubt hates her.
What did she do to deserve his hate?
The person who she treated well like a brother did not even bother to notice it...

Years passed…

He needs to get married.
He needed a wife.
So she offered herself.
It was a marriage that will benefit both parties he said.