MTL - Marvel: Start with Summoning the Shadow Troopers - Chapter 8

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.

Gu Nianzhi had no idea how to get the aloof and handsome Major General to fall in love with her.

His eyes were dark and serious. “…Seduce me. If you can do it, I’m yours.”

Gu Nianzhi: “!!!”

- Description from Novelupdates

A girl who calls herself a demon appeared before a timid student named Fumio Kijima. The girl claims to be a campaign girl from the demon world and she gives him the ability to “summon a room” from nothing but thin air.

At first he doesn’t abuse his power and uses it as a convenient ability in his every day life. But one day he is bullied by his classmates under a false pretext and is made to suffer. In the past he would have wallowed in misery and cried himself to sleep, but now he had a power to call upon.

“I will make them regret it!”

Using his powers to summon his “room”, he begins his era of confinement and brainwashing to achieve his goals.

The youngest A-rank adventurer, child prodigy Kaizer, finds three babies who were the only survivor of a destroyed village. Then he decided to give up his job as an adventurer and raise them. Over time, the girls grow brightly and show exceptional talents in fencing, magic and management. However, these girls also seem to love their father, Kaiser!