Making a harem after transmigrating - Chapter 40: One down, one more to go (R-18)

Enter Kazuya, a boy who never had any memories before his adolescent life. He was summoned to the world of Edea wherein the final battle against the Demon King, our hero entered the last room to find a welcome he had not been expecting. An unguarded, unarmed demon king who greeted him with manners and etiquette.As if a respectful and well mannered final boss wasn't shocking enough, he was then introduced into an elaborate plot to exploit summoned heroes. Unfortunately, our naive hero chose to trust his companions. He underestimated human greed which led him to suffer alone in darkness for a time he himself does not know how long.When he suddenly woke up, he saw himself as a child back on Earth. As an amnesiac, he had been thrown into an unknown part of his life. What should he do? What about the people who betrayed him?Follow along as Kazuya finds out about his past and tries to prevent the tragedies he's experienced while trying to change what he knows what will happen in his future.Volume Guide:I - From the Ashes. (Learning about his life before he lost his memories)II - Divergence. (Changing the future)III - The Two Heroes.IV - Edea and The HeroV - ???VI - ???VII - ???VIII - ???

One day, Luo Jian woke up from his sleep and found himself in a locked chamber where the door and window were all sealed. A note with a few lines written on it was tacked to the wall: “Escape from this room within an hour, otherwise, you will die.”

There is a sequel called Reincarnation Night (轮回之夜) that takes place in the same universe but has different main characters

- Description from Novelupdates

A young boy genius, Suo Jia, is a water mage who dreams of being a warrior travelling the great and dangerous trade routes to find his lost father that set off on them before Suo Jia was born. Having to look after his sick mother, Suo Jia manages to find a way to solve all their problems, as well as make a name for himself. He gathers nobility, vast wealth, items of great power, knowledge lost to the ages, and exceptionally talented females around him as he plots and plans – preparing to set off on an epic journey that will go down in history as a new legend. However, will others that depend on his powers so much be willing to let him go on such a dangerous journey so easily?

- Description from Novelupdates