The Last Incubus with The Vice and Valor System - Chapter 172 sorry

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.

How long would a marriage be able to sustain itself when it had nothing to do with love? Then how would a marriage based merely on power and a monetary transaction be able to last?

The person in Shang Yushang’s embrace was his male wife. A temporary wife that was bought to get rid of bad luck. But ever since the moment he had this person in his arms, he decided not to let go of him.

He Changning obeyed his so-called family’s decision and married himself off. Thinking that, when this transaction was over, he can live his own life happily ever after. But, little did he know that he had just stepped into a big net filled with warmth that was specially woven for him, and that he would never have a chance to get out of it.

- Description from Novelupdates

Kōdo Ikusei Senior High School, a leading prestigious school with state-of-the-art facilities where nearly 100% of students go on to university or find employment. The students there have the freedom to wear any hairstyle and bring any personal effects they desire. Kōdo Ikusei is a paradise-like school, but the truth is that only the most superior of students receive favorable treatment.

The protagonist Kiyotaka Ayanokōji is a student of D-class, which is where the school dumps its “inferior” students in order to ridicule them. For a certain reason, Kiyotaka was careless on his entrance examination, and was put in D-class. After meeting Suzune Horikita and Kikyō Kushida, two other students in his class, Kiyotaka’s situation begins to change.

An angel made a mistake, resulting in Shiihara Daiki’s death. In order to hide the mistake, he was then sent to a different world. The angel will grant him one wish as a payment for keeping it a secret. Daiki asked for a Heavenly Castle floating in the sky without hesitation.

Suddenly a floating castle appeared in the new world, which causes confusion amongst the people. They attempt to contact Daiki in various ways. A country tries to steal it by force, while another seeks to befriend him. What in the world would Daiki do?