King of Nine Skies - Chapter 17 - 0:Sonic Crag

Kusumi Chiharu gets a message one day that he has been selected as a Monster Tamer, and he is prompted to select his first partner. He thinks little of the message until he receives a giant package the following day. He assumes it’s the porn books he ordered, but the huge box ends up containing the unconscious body of a near-naked girl! She’s a ghoul named Zonmi, who intends to fight beside him as his partner.

However, it turns out that other hot girls at his mostly-male high school are also magical entities, and Zonmi may not be the only one who wants to fight by his side!

“I beg you, please teach me how to pick up female angels!!!”
Pleaded the twelve-winged angel.

“Teacher!! How can I fool more people into my sect?”
Asked a devil in the devil world.

“Do you know how to save the family cat that died last night?”
Someone in the sky is too embarrassed and asks me quietly.

“All the angel, all the big deity, please I am not God, I am really just a summoner….”
I said painfully.

This is the story of a poor boy and how he becomes the greatest summoner who dominates the six worlds because of an accidental acquisition of Dimension.

- Description from Novelupdates

Aku was not the hero destined to save the world, nor the princess destined to be rescued.He was the demon king. Born without a name, without form, without freedom, predestined to die at the hands of the hero from his birth.However, Aku decided to defy fate. He took over the hero's body to find his freedom.It was then that an angel spoke to him, believing he was the hero who had failed to defeat the demon king.The angel told him that countless worlds and countless demon kings existed; those heroes who failed their mission were sent to an academy to amend their mistake.Now Aku will find himself caught up in battles with other demon kings and wars in other worlds while deciding whether to choose the path of good or allow himself to be consumed by darkness.