MTL - The Little Merman - Chapter 71

Dong Xi transmigrated, but she was neither the female lead nor the villainess, but a tragic side character in a book. Even though she was a proper rich daughter, her mother used her as a substitute for her youngest sister, and sent her to train as a cultivator at the top cultivator sect in the world. Though she was initiated at eight years old and trained for eight years, she was talentless and didn’t have much experience. Eventually, her younger sister was recruited because of her outstanding talent, while Dong Xi was banished after it was revealed that she was just a substitute.

After that, someone caught her, imprisoned her, and tormented her for two years just because she was attractive. Though she was rescued by a senior disciple from the cultivator sect, it turned out that he did it to avenge her younger sister, and tortured her to death. When Dong Xi transmigrated, it was just after she was initiated and began life as a cultivator. She decided that she would do her best, improve her cultivation, and survive! Eating? Sleeping? All that was a waste of time! If there was a cultivator who practiced sword cultivation a thousand times per day, she would do two thousand!

Eight years later, when her younger sister was recruited for her talent, Dong Xi promptly packed her bags and left, leaving the cultivator sect panicking and wondering who had taken her away! Su Cheng, the most powerful demon lord: Who dares harm my beloved wife?! This means war! Dong Xi, still running away: What? Who are you? Su Cheng: Don’t you remember the snake you counted stars with years ago, beloved?

She shouldn’t have got drunk, so she wouldn’t have court the troubles.
She slept with a handsome man and would be sent to the police?
Oh, my sweet Jesus…
“So you just ran away like nothing happened after you slept with me?”
“Old jerk! Even if I had the initiative, it was you who took advantage of me!”
As a saying goes, the more spoiled a president gets, the more likely he becomes a scumbag.
An adorable ‘wildcat’ vs. a scheming frenemy.
This was a love rivalry between a modern Cinderella and a Big Boss.
As time flew, the world was like a fleeting show.
When they met again after several years of separation, he held her hand tightly and swore that he would never give her any chance to leave him again!
Finally, he asked her to marry him and pampered his cute wifey with his endless love.

- Description from Novelupdates

Kuramoto Daisuke, a freshman in High School was suddenly exposed to someone vanishing in front of him. Turns out he was admitted to a Special Class full of Isekai Heroes that were regularly summoned to Otherworlds since the start of their Middle School. He was told that he was to become their Support to prevent each of the Heroes' fate of dying in the world they were summoned into. Though mediocre, he realized that his ability has a great potential but it needs a lot of hard work on his part.

Unconvinced of being just the Support Character, he vowed to excavate his mediocre ability, all the while supporting the Heroes using it.

And maybe more.

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates