In JJK With Naruto Powers - Chapter 45: Confessing to Mei Mei

A campus bullying incident led Chu Feng to receive a message of Rong Yun’s suicide after ten years.

Rong Yun’s relic is a novel based on him…

At this point, he came to know that Rong Yun had always liked him.

In deep regret, Chu Feng returned back to high school.

This time, he wants to protect Rong Yun, his achievement and let him have a different life.
At first, he only wants to compensate for his mistakes, but he didn’t know when his compensation become’s true love.

- Description from Novelupdates

Ajax used to coast through life before his parents died, after that he focused hard to try get his life back on track but that wasn't really happening and it all ended the day he got mugged. Given a second chance at life he now looks to become someone who matters and is willing to work hard from the beginning to make that happen.

After reviving unexpectedly, the concubine’s daughter was no longer a coward like before, but a hard nut.

Flamed her up and bullied her?

Come on!

She came from the 21st century! How could she willingly embrace such destiny?

“Since you ask for it, see how I will torture you!”

She punished the scums and struggled against bad minions!

See how the concubine’s daughter Dong Ling would stand up and master her own fate!

- Description from Novelupdates

I can be the main character even though I’m not a hunter. Kang Moo-hyuk succeeded in all the raids with his genius and rose to the position of Strategic Team Leader despite not being a hunter.But one day, he got diagnosed with a terminal illness called “mana addiction”, and even got involved in a power struggle within the guild. With only a few days left to live, he decided to do everything he every wanted and set his passions ablaze. And he chose the tier 1 “Taesung Guild” to do so.But how can Kang Moo-hyuk grow the guild with Joo Se-ah when the rest of its members are amateurs?