City of Sin (Yanyu Jiangnan) - Vol 9 Chapter 139

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!?

Once again, as he opened his eyes, Ning Changge awakened his extraordinary insight, only to find himself reborn as an abandoned infant.Coincidentally, Zhang Sanfeng passed by and took him in as his eighth disciple.From then on, on Wudang Mountain, there was an unparalleled prodigy with extraordinary insight. While others practiced martial arts or cultivated immortality, Ning Changge aimed to forge a path to eternal life in the world of martial arts!【You studied three thousand classic scriptures, mastered three hundred inner cultivation techniques, and, with your innate inner energy, created the “Eternal Green Immortal Technique”!】【Reading a hundred volumes of swordsmanship, observing battles between peerless swordsmen, you gained insights and created the “Gold-ranked White Tiger Sword Qi”!】【You established the Immortal Sect, spread the teachings of immortality, and led people around the world to cultivate immortality. You observed the path of mortals cultivating immortality and used their inspiration as nourishment, creating the “Great Dao Elemental Infant Condensation Technique”!】【You led the world to ascend, and the world’s will rewarded you with the Supreme Merit Golden Dragon feedback. You refused to absorb it, pondered carefully, and created the “Supreme Merit Body Forging Technique”!】Martial techniques, passing them on to others…

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!