Tsuujou Kougeki ga Zentai Kougeki de Ni-kai Kougeki no Okaa-san wa Suki desu ka? - Volume 1 - Chapter 6: Epilogue

She, the world's chief doctor of the 21st century, the legendary overlord of the medical world, was killed and her soul transmigrated…She, the useless miss of the Windcloud Empire, was ugly, silly, and obsessed! She died in her own sister and fiancé's hands…When she reopened her eyes again, she had the soul of the strong but the body of the weak…When she became her, her fate would be rewritten and a miracle would appear…This was a story of a two-faced person meeting another two-faced person. With pure hearts, they would end up together.

A novel revolving around being transported to another world with an op system. The mc spends his day chasing skirts and doing missions to level up. A standard journey to the top with lots of girls from various animes and games with a twist of that gaming feel (hunting mobs, doing missions).

- Description from novelupdates

After 20 years of dedicating his life to opera ever since he had quit the performing arts high school, he had failed at an interview. Losing his motivations, Jo Yunjae depended on alcohol to live out his days until one day, he had been sent back 20 years in time, to the day before his high school admission.