Akuyaku Reijou ni Nanka Narimasen. Watashi wa『Futsuu』no Koushaku Reijou desu! - Chapter 173.1: Business at the castle and Grandfather.

After dying in an oddly anticlimactic vending machine accident, Kazuki Ren is reincarnated in the demon realm—not as a hero, not as a villain, but as the only human male student enrolled at the mysterious Academy of Ruin, a school where all the professors are demon lords and all the students are powerful, beautiful she-demons.Ren is told he has one task: survive.But there’s a catch. The Academy’s darkest secret is about to awaken, and Ren holds a hidden power that could either destroy the demon world... or rule it.Now surrounded by seductive demons with hidden motives, eldritch tomes, forbidden dungeons, and twisted exams, Ren must master his ability—or be consumed.Magic, mystery, danger, and temptation await in this dark academia harem fantasy.

Amakawa Haruto died before he’d the chance to reunite with his childhood friend who disappeared five years ago. Rio, a young boy living in the slums seeks revenge for his mother who was murdered in cold blood in front of him when he was only five years of age.

There exists the earth many knows of and there exists an alternate world. Two people, each with their own backgrounds and values. For odd reasons, the memories and personality of Haruto, one who should have died resurrects in Rio’s body. As the two are confused over their memories and personality fusing together, Rio (Haruto) decides to live in this new world.

Along with Haruto’s memories, Rio awakens an unknown but special power. If he’s to use it, it looks as if he can live a better life, but before that, Rio encountered a kidnapping which results in involving the two princesses of the Bertam Kingdom.

After saving the princesses, Rio is given a scholarship to attend the Royal Academy, a school for the rich and powerful. His background being a poor orphan who once lived in the slums, the school full of nobles was rather a detestable place to stay at.

When the spiritual barrier that has been intact for a hundred years is shattered by a meteor, spiritual energy that had disappeared starts to return.The mystical realm slowly begins its revival—magic, witchcraft, curses, supernatural lifeforms, strange and mysterious legends, monsters and gods from other worlds…The old world order collapses, yet the new order is mystifying and chaotic.Just before the unprecedented reformation is here, Tang Qi awakens and finds himself hung on the cross, having turned into an inferior demon and in great pain and agony…With his special ability to see through the nature of all things from the mystical realm and a sly and crafty mind, follow Tang Qi as he develops new skills and powers—as well as making new friends and allies—to battle and protect himself from never before seen supernatural threats in an unfamiliar world!

220 years ago, in the legendary Dragon Demon War, Hero Azell ended the war by killing the evil Dragon Demon race’s King Atein. He was able to save the population, but as a consequence, he was cursed. While he was dying, the high magician suggested a gamble that might save his life.