Instead of Checking In Regularly: I Hide And Cultivate In The Monster-quelling Tower And Become Invincible - Chapter 621: Mortals can live thousands of years

She died in her prime as the Queen of Song.

After being reincarnated, she becomes a simple trainee.

Losing her former glory? It doesn’t matter—no one can compete with her voice as a beautiful singer.

Mocked by her lowly birth? It doesn’t matter—her true identity is enough to make the whole world tremble.

She owes huge debts? It doesn’t matter…

A powerful boss once whispered to her, “Your debt will disappear if you become my woman.”

But the proud her would reply, “I’m sorry. I would sell my art, but not myself.”

- Description from Novelupdates

A man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his rigorous discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life. This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.

Cain was living his best life as the leader of CROSS, a gang ruling Zone A, District 4.At 21, thanks to constant cigarettes and booze, he looked older than his years. He didn’t finish college or have a job, but he made a living through “guard fees” from local markets and his shady side business.One night, his life turned upside down when a shooting star crashed through his window, transforming into a cute fairy girl in a pink dress and rabbit hat, who declared herself the Idol-Idol Goddess!Now, Cain has to juggle being a gang leader and a rising idol star. Can he balance both lives without blowing his cover?[RPG System Style. No Harem. Drama. Romance. Face Slapping. Idol. Magical Realism. Urban Setting. Beautiful Female Lead. Strong ML. Smart ML. Handsome ML. Cold ML] XD