A New World, an immersive game experience - Chapter 723 Jade

In regards to the MMORPG Cross Reverie, Sakamoto Takuma boasted an overwhelming strength that was enough for him to be called the Demon King by the other players. One day, he gets summoned to another world with his appearance in the game. There, there are two people that insist “I am the real summon master.” Takuma gets slave-turning magic used for summoned beasts cast on him by the girls –

The celestial celestial beings who lived for more than 100,000 years were born and reborn in a small monk in a human world.
His motto: “It’s not as good as a medicinal medicine for ten years of hard work.” “Even if you practice a copper-iron bone, it’s not enough for my soldier’s attack.”

- Description from Novelupdates

For non anime fans- Yandere is extremely possessive girlsIn an open world MMORPG game called Stellaris Fantasia Online, me and my partner we're rising to the top, killing other players, farming loots and so on....But, yes, this partner of mine won't let me play with others.... even with my friendswhy? because she's a Yandere....Its so irritable that I unfollowed her.... well that decision hurts me too, since she might turns out to be a hot onee-san (older woman)But as soon as I attend the class, my homeroom teacher is in bad mood...Why??Just read the title....

This is a world where a king is the most powerful.