Pokemon: The Gameboy Effect - Chapter 28: The Queen’s Grand Showcase

[The 3000th Descent of Mystery is about to begin.][This is your only chance to redeem yourself.]When the whole world was in danger, Wang Teng activated a unique talent.It was the Rank SSS talent - Inequivalent Exchange!He was not purchasing things for free, but the exchange was not equivalent.[Exchange successfully. You used half a bowl of cup noodles. With your Rank SSS talent, you may retrieve an unlimited supply of cup noodles.][Exchange successfully. You used a bottle of Sad Breeze wine to exchange for the Star Shifting Method.]…From then on, Wang Teng activated a new exchange system.

Before getting married, Shen Xi knew that her fiancee had a girl he was secretly in love with for years.
After the divorce, she found out that the girl was her.

Before getting married, Shen Xi knew that there was going to be no love in her marriage.
After the divorce, she found that her ex-husband had married for love.

Before their marriage, her husband had a lot of money.
After the divorce, her ex-husband went bankrupt paying for the huge alimony.

Then, Shen Xi was reborn to the day of their marriage.
Shen Xi would just like to ask, would it kill you to say ‘I like you’??

- Description from Novelupdates

The world had changed when the System arrived, alongside the Cataclysm that filled the world with monsters. The technology was gone, replaced by classes and skills that allowed the people to fight back. When Devon ended up as a Blacksmith, a class that didn’t grant Intelligence, he had to face the reality, that his old career that he loved - mathematical sociologist - was over. Instead, he had ended up as yet another discarded member of the production class, overshadowed by the existence of the System Shops to the point of total marginalization. But, what if all he needed was to reapply his scientific thinking to the System...

What will happen if your ordinary life becomes not so ordinary? What will happen if your old existence becomes anew? What will happen if the world that you know is changing?

Our heroine, Anne, is a 40 year old librarian, that got entangled in mythical magic, inside a mysterious fairytale book. When the disaster happened, she got thrown into another world, the kingdom of Valorian, where magic and lore are coming alive. A world where she becomes younger again, but with a wisdom and knowledge of a forty-year-old woman.