MTL - As the Minor Gay Rival in Het Novels - Chapter 51

Dumbledore always believed Voldemort was the greatest threat to the wizarding world until a thousand-year-old vampire showed up at Hogwarts with the deed in hand—“A thousand years have passed, and Hogwarts' lease is up!” said Dracula. “Headmaster, you wouldn't want your students to be homeless, would you?”“What do you want?” Dumbledore asked gravely.“Anything interesting.”“Well, I think the position of Defense Against the Dark Arts professor is quite interesting!”...And so, Hogwarts gained a professor who couldn’t be dismissed.McGonagall: “Albus, I don't think Professor Dracula's teaching is suitable for the poor children!”Dumbledore: “There's nothing I can do, no one can fire him.”...Draco: “My father is a governor, I'll have him get you fired!”Lucius slapped Draco on the head, “Mr. Dracula, Draco speaks without thinking. Please, don't fire the Board of Governors!”...This is the story of a vampire who lived too long and found amusement in the wizarding world out of sheer boredom.

A seafood chef inexplicably transmigrated into ancient times. Even though he landed in a family with a nobility rank, and theoretically was supposed to be rich, the most valuable thing in the house is a grey donkey…
Su Yu stared at the sky helplessly; in order to support the family, he could only take up his old profession and go out to sell fish.
Unfortunately, the royal family selected concubines from both genders. Even as a poor noble, he had no choice but to attend…
DISCUSSION TOPIC: Will I be selected if I display my fish-slaughtering skills?
“Meow!” His Imperial Majesty shook his tail.

- Description from Novelupdates

When The Cute Kunoichis Spied on Their Teacher's Secret is a light novel written by Kazuma Kamachi and illustrated by Ryuushi Tajima.

The story takes place in a world where Japan never ended their isolationist phase, and agents from foreign powers are always threatening to steal the country's advanced technology. In order to combat this threat there has been a resurgence of ninjas that use Strategic Martial Arts, techniques that combine cutting-edge modern technology with a traditional foundation of martial arts and ninjutsu. The story follows Souha Sugiyado, a 17-year old ninja instructor and former ninja prodigy who was forced to retire from active duty by the wounds he suffered in his last mission. Souha's four students are all kunoichi who have all gained the rank of Elite Ninja, the highest official rank available to ninja. However, one day two Shogunate ninja approach him with the news that his four students have gone rogue and have stolen a portable modular nuclear reactor, and thus they ask for his help in bringing his students to justice.