One Piece: King of the World - Chapter 359: I’ve been fooled by that damn schemer for so many years!

After years of longing, Mu Chenyan was finally going to marry the man of her dreams — Yuan Xuan. However, on her wedding day, the tragic death of Shu Qinger, her well-known romantic competitor led to Mu Chenyan’s prison sentence.

An engagement paper to lock one’s destiny. With her family facing financial difficulties, she marries into the family of the richest man in Qingzhou as his wife. Her Mother-In-Law’s doubtfulness; her husband’s childhood sweetheart; her mean elder sister-in-law; her narrow-minded younger sister-in-law… Being inferior, Sang Wan withdraws without a choice. As time passed, she ended up being lonely and died tragically.

Reborn on a sedan chair, how shall she proceed? Standing right at the cause of the tragedy when everything restarts, can she change her fate and find her beautiful melody?

- 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.