Tatakau Shisho - Volume 10, Chapter 5: Final Battle of the Armed Librarians – Part 3

Based on the popular Vocaloid series, by HoneyWorks, called “Kokuhoku Yokou Renshuu (Confession Rehearsal)“:

Natsuki, a third-year at Sakuragaoka High School, who holds unrequited feelings for her childhood friend, Yuu, who’s in the Film Club. However, instead of being honest about her feelings, she makes him be her confession “rehearsal” partner. Unable to say her true feelings, things start to get complicated when Miou and Akari, who are also in the Art Club, get involved! Will she ever be able to confess for real!?

Jung Sunwoo was an average man. He had just taken his first job at W&U, a celebrity management company, as a manager. He could finally achieve his dream of being the manager of a world-famous actor or actress. On his way to work, he fell into what appeared to be a lucid dream about his future. As he went on with his day, he realized it may not have simply been a lucid dream.

Lu Zhengfei personally killed Chen Qianqing with his abuse.

He cut off Chen Qianqing’s legs, and blinded his eyes, locking him up with chains in his house. Then, he watched with his eyes wide as he died. Injuries inflicted in the name of love would always end in a tragedy.

Did Lu Zhengfei regret it? Of course he did. And so, God gave him a chance to be reborn.

But this time, he found that he himself——became Chen Qianqing.

- Description from Novelupdates

An otaku with a hobby of masturbating was reincarnated as the son of a great mage.

As soon as he was born in this life, he vowed with a goal of embracing women till his death.

That said, when he became 20 years old, the Demon Lord which was sealed by his ancestors revived, and now it is his role to seal it once again.

And that demon lord is sealed in a tower dungeon that is rumored to be impossible to capture.

However, by an unexpected coincidence, he had found out that the Demon Lord is also one of him, a kindred spirit from within,

so he joined her instead and filled several traps in the tower dungeon, and thus they enjoyed a s*x spree with all the women coming over!