How I Accidentally Married a Billionaire - Chapter 4 -

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 end of all worlds approaches.

The Demon King Order harvests lives from all manners of living beings.

Within this darkness full of despair,
A single person escaped from space-time, returned to before the world collapsed, determined to change the fate of the past.

But as time pass, he gradually finds out that the Apocalypse isn’t quite as simple as he thinks…

Hai Xiu has a slight social disorder. After he transfered school, his new teacher tried to help him to treat it slowly by giving him the task of sending and receiving homework and test paper from his fellow classmates. Although Hai Xiu has communication problem, he still stumbled around trying his best to do so. However, he accidentally misplaced the test paper of the school’s resident “bad student”… And thus, started their sweet story together…

- Description from Novelupdates