Dragoon - Dragoon 5: The Pickup Boy and the Reincarnated Boy

Two heroes of the game Legend of Heroes 2 who were rotten waters*.

Juvenile Luo Yang, because of the body being blocked by evil dragons, and with the blood of God, has embarked on a road to heaven! Rise from the humble, turn the mountains and seas, step into the world, and press the heavens!

- Description from 69shu translation

After traveling for three years, Lin Yu was drawn into a horror game unexpectedly.

However, he discovered one thing.

The dungeon boss feared by countless players turned out to be the little loli who called her big brother next door.

then.

In the horror hospital, the director of the hospital turned out to be the uncle downstairs who made him and his granddaughter fall in love.

In the bloody slaughterhouse, the existence known as the bloody butcher turned out to be the uncle upstairs who wanted him to be his brother-in-law.

In Changteng Ghost School, the woman who frightens countless students is actually the long-legged sister Yu who invites her to her house for dinner whenever she has nothing to do.

…

Traveling through three years, you told me that this place is actually a horror game world?

(Introduction is weak, please read the text)

- Description from novelbuddy

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.