Reincarnated as the Crown Prince - Chapter 28: Time to Modernize

For the large sum of money to help her husband, she chose to be a surrogate mother covertly. Her sweetheart was out of trouble, but she became the woman of loose morals in his eyes. Misunderstanding, disappointment and sadness forced her to divorce the man she loved from the childhood.

When she was determined to start new life, another man burst into her life. “You are my baby’s mommy and you are my wife!” A big surprise hit her that her baby’s Daddy, the man she surrogated for, fell in love with her at his first sight.

His deep love convinced her to believe the affection of love again. Unexpectedly, her ex-husband returned to beg her recombination. One was her childhood sweetheart, and the other was the man who loved her and gave her hope for a new life……Facing the two men, what is her choice?
 

- 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.

Xiao Rou, a girl growing up in a poor countryside family, finds that she’s actually the daughter of a wealthy couple. Her mother had mistaken another girl for her back at the hospital. Thinking she would change from an ugly duckling to a noble swan and live happily ever after with her real family, reality strikes her in the face.

[Post-apocalyptic + System Space + Stockpiling + Base Building + Strong Female Lead + Reverse Harem + Not a Mary Sue]Who says a five-year-old can only be a burden?Cloud Xiaoxiao, a formidable survivor in the post-apocalyptic world, is reborn six days before the apocalypse hits. Unloved by both parents and unwanted after their divorce, she decides to take matters into her own hands.At just five years old, she goes on a rampage. She empties out her father’s supermarkets and 4S car dealerships, landing him in the hospital.Armed with a super system in a world ravaged by zombies, extreme temperatures, and acid rain, she hoards enough supplies to last several lifetimes. She becomes a base-building maniac, constructing the strongest fortress in the post-apocalyptic world.Sunny Boy Next Door: “Little one, want big brother to sing you a lullaby?”Unlucky Bandit: “Kid, what do you want? I’ll get it for you.”Cool Big Brother: “Don’t be afraid. I’m here.”Yandere Hottie: “Little one, call me big brother and I’ll kill them all for you. How about that?”Hot-Tempered Brawler: “Shorty, who’s bullying you? I’ll beat them to death!”…Cloud Xiaoxiao hastily raises her hand, “Stop, stop! I can take on ten at once!”“Whoever dares to bully me, I’ll finish them off myself!”(This story has no romantic pairings. Readers who mind this, please be cautious.)(The female lead appears innocent on the outside but is actually a wolf in sheep’s clothing. Her personality was shaped by the post-apocalyptic world, growing beyond the bounds of normal rules. So she’s a bit ruthless, a bit wild, a bit wicked…)