Re-Birth Of A Genius. Creator/Destroyer - Chapter 2435: Testing each other

A small immortal clan, with the efforts of the ancestors of the past dynasties, slowly developed into an immortal clan. This is the history of the development and growth of a small family. During this period, there were ups and downs, and there were also struggles for power and profit.

- Description from novelbuddy

What’s not to love about my new life after transmigrating into a Pet-centered world?
There are mighty creatures that come in all shapes and sizes. They can either be cuddly companions, helpers in your daily life, daring scouts or strong fighters. Or all of the above. Not bad, huh?

I have a family, but the fact is completely overshadowed by my younger sister. She thoroughly hates my guts, and she makes sure that I know this. Every. Single. Day.
Did I mention that she’s disgustingly talented while I am a bottom feeder? A terribly handsome one at that.

I have free rein to run the family business on my own. A small and quaint Pet Store. It should have been great if not for the fact that the previous owner of this body was born with ZERO affinity to handle Astral Pets…

It wouldn’t be a proper transmigration without a gimmick or a system to pave my road to greatness, don’t you think? I have one, but I don’t know if I would be better off without it…

Mimizuku, a small girl with chains on her wrists and ankles and the numbers “332” branded onto her forehead, wanders into the Forest of Night seeking to be eaten by a monster. However, when the ruler of the monsters, the mysterious and beautiful “King of Night,” refuses to eat her, she tries to formulate a way to convince him otherwise.

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.