A Mistaken Marriage Match: Mysteries in the Imperial Harem - Chapter 68

Xiao Chen, “the waste” of Xiao clan, had his engagement to the Young Lady of the Yang clan renounced.

And when he arrived at the sect that sympathized with him and took him in, he found corpses strewn all over the place and a mist of blood in the air. The sect was exterminated by a mysterious group that was looking for the ‘Wind Spirit Jade’.

He himself was left behind only half-dead for ‘wastes do not deserve to die by their hand’. Humiliated once more and on the verge of death, in the surroundings strangeness happened. A whirlpool sucked up the blood mist and diverted it into Xiao Chen’s forehead, transforming and enhancing his body.

- Description from Novelupdates

Zhou Heng drank too much wine, and woke up to find that he had time-traveled, and there was a beautiful woman lying beside him. Just when Zhou Heng, a bachelor of ten thousand years, wanted to take charge, he suddenly discovered that this woman who had a relationship with him was called Sadako, and she was the Sadako in Midnight Ring.

Sadako is just Sadako, pretty and human, but the memories that come out one after another make Zhou Heng discover that his name is Takeo Saeki, and he is the husband of Kayako in the Grudge of the Great Evil Spirit.

Later, at work, Zhou Heng discovered that his female colleague had a strange identity. The daughter of his client, Mimiko Mizunuma, had always been very interested in him when she came into contact with him.

- Description from novelbuddy

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.

Before going to college, an ordinary high school student went to celebrate and got drunk. When he woke up, he found himself in a completely different world. There was a big sect, the approaching sect entrance examination, a slum where his body’s previous owner lived, and a shared memory about a missing young girl.