World football system - Chapter 54: Cold Nights, Hot Rivalries

Haruto Hayase was a normal high school boy in his third year, living a quiet life until his younger sister, Haruka Hayase, joined the same school. Haruka’s beauty and charm made her the center of attention, quickly becoming the school’s prima donna. But when a notorious gang leader set his sights on her, he did everything in his power to protect her—only to fail tragically. Haruka was brutally assaulted and tortured, and Haruto himself suffered an agonizing death. However, in a twist of fate, Haruto is given a second chance, waking up a year before the events that shattered his life. Armed with the mysterious ‘Debauchery System Slave’, he vows to exact revenge on those responsible. This time, he will use his newfound powers of the system and charm to seduce the loved ones of his enemies. From their mothers, sisters, and lovers to their closest friends, Haruto will make them his. His enemies will suffer as he steals what they hold dearest, ensuring their downfall in the most devastating way possible.

The story begins with the last day of Yggdrasil, a popular online game which is being quietly shut down. Our protagonist Momonga decides to stay in his beloved game until the last moment, so waits for the forced logout. Unexpectedly, the server does not shut down and Momonga is stuck in a skeleton avatar in another world. “The powerful Overlord” needs now to discover the new world and face the continuous challenges that arise.

A little ruffian who fought recklessly without any morals and bottomline accidentally time-traveled to parallel space and became a Key Case Investigation Team agent. The huge change in identity had him creating chaos in the police station. However, a strange miracle system helped him repeatedly solve mysterious cases, turning him into an impudent ruffian detective!

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

- Description from Novelupdates