The Record Of Barton's Fantastical Events - Chapter 12

In the current era, people are either normal or are with ‘special abilities’. Cases related to the latter are managed by the “National Anomaly Prevention and Control and Special Species Management Office”.
Qi Zheng Emperor Sheng Lingyuan was reawakened a thousand years later after he jumped off the fiery Red Lake. Xuan Ji, a newly transferred staff to the Reparations Division of the Deviant Control Office, finds himself having to clean up the mess of a revived tyrannical monarch. The two seemed to share something from the past, but unbeknownst to them, a big conspiracy is stirring right underneath their noses that could destroy the balance of the world.

- 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.

“Shit, why this guy!?”Of all the unique characters he could’ve transmigrated as, it had to be the bastard instructor.Vanitas Astrea.A third-rate middle game boss, who was dismissed from the University after severe allegations, losing his teaching profession and ultimately, exiled from the Empire.“.....How did I even get here!?”Vanitas must now circumvent his way around this new world, confront his past, mend broken relationships, and prevent looming tragedies that would lead to his demise.

Born with amazing talent and mastery of the sword, at age 13 he awakened his memory about the world thus setting out his own journey and create a world that is for himself and his crew onlyAt the age of seventeen, he went to sea, joined the Rocks Pirates, participated in the Battle of God Valley, plundered the treasures of the Celestial Dragons, formed his own pirate group, competed for the throne of the Four Emperors in the New World, and became the world's number one swordsman.The most powerful attack and the most powerful defense are gathered in one person, and finally became the strongest in the world.Before the war on the top, he helped Whitebeard restore his peak strength. When Whitebeard attracted the attention of the whole world, Li Yuan led his pirate group to attack the Celestial Dragon Holy Land Mary Geoise...