Gina's activites

After twelve years, a former teammate—no, a thorn in his side—suddenly reappears. Eunsan...

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stories where characters regret letting go or leaving the 
female lead, mostly romance and some family related

https://www.mangago.me/home/mangalist/3061174/ (2)

Zhi Banyi has a secret. His heart only beats faster when he listens to a streamer called "Dust ...

All Isaac the beta wants is to live a normal life as a slightly unskilled florist and leave his turb...

Frede, the most handsome bachelor of the empire is marrying Ayla, the only daughter of the powerful ...

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Chung Myung, The 13th Disciple of the Great Flowery Mountain Sect, One of the 3 Great Swordsmen, Plu...

This is just a list of manhwa/manga which has main character/s who gained a second life in the modern world setup.

Main Characters: Reincarnated/Second Life
Settings: Modern Society

The list is in no particular order.
Feel free to suggest anything in the comment section.

There are also altruistic people in the selfish world. "Nothing is more precious than human life. Is...

Being an Elite Nanny is simple: protect the charge, obey the principle, and don't get emotional...

After being held in disdain and having his life put in danger, an orphan from the Demonic Cult, Cheo...

Different from others, playboy Ryu Jihyun falls in love with the pure-hearted Han Yohan. Though Jihy...