As long as you have the courage, fierce ghosts go on maternity leave. - Chapter 9: Awards

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.

Finding himself in an Last Airbender without an airbender around, a transmigrator waterbender goes on an adventure to stop the worst from happening to him.

He is a legendary business powerhouse, a King with a business empire. She is just an ordinary female student. A deal, – a paper marriage, a marriage for four years. Four years later, she turned away fearlessly. She thought that their path would never cross again, but he took her in his stride and refused to let go of everything about her, even interfering with her getting close to other men!

Jiang Su transmigrated.

He transmigrated into a BL harem novel as the novel’s main character, jianghu’s number one beauty, who bewitches the masses with just his face, then is subjected to shame, humiliation, and infamy at the end.

To prevent this from happening, Jiang Su diligently practiced his swordsmanship. But then he suddenly realized…If he is still single when the original storyline ends, he will be forced to return to his original world.

Jiang Su: ……

- Description from Novelupdates