Spending My Retirement In A Game - Chapter 729 An eye for an eye

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.

A mysterious teenager who had lost his past, awakened in Tianlong Continent. Mistaken as the Ye family’s Son, he used this identity to observe this chaotic world and to search for his past self, but only to find an inevitable and terrible fate, therefore he indignantly laughed at his destiny, and revealed his prowess to rule the lands under the heavens.

Since then, the air and the clouds moved with his hands, and even thunderstorms were subject to his palms! He, as the fairytale’s main character, had shocked the people of Tianlong Continent with his legendary prowess and intelligence, but the extent of his powers were still unknown.

- Description from novelupdates

After 20 years of dedicating his life to opera ever since he had quit the performing arts high school, he had failed at an interview. Losing his motivations, Jo Yunjae depended on alcohol to live out his days until one day, he had been sent back 20 years in time, to the day before his high school admission.

Traversing into another world, Zhang Xuan finds himself becoming an honorable teacher.

Along with his transcension, a mysterious library appears in his mind.

As long as it is something he has seen, regardless of whether it is a human or an object, a book on its weaknesses will be automatically compiled in the library.

Thus, he becomes formidable.

“Emperor Zhuoyang, why do you detest wearing your underwear so much? As an emperor, can’t you pay a little more attention to your image?”

“Fairy Linglong, you can always look for me if you find yourself unable to sleep at night. I am skilled in lullabies!”

“And you, Demon Lord Qiankun! Can you cut down on the garlic? Are you trying to kill me with that stench?”

This is an incredible story about teachers and students, grooming and guiding the greatest experts in the world!

- Description from Novelupdates