I'll Teach You, Marianne. - Chapter 737 - Jacks Belonging

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.

On the night of his marriage proposal, Xu Yang was dumped by his ex-girlfriend.Feeling heavy-hearted, he went to a bar to drown his sorrows.He didn’t remember much about what happened that night, but he woke up with a stunning beauty lying next to him. At first glance, she looked somewhat familiar.Wasn’t she his ex-girlfriend’s sister?And it seemed like she was about to wake up!What should he do? He’s anxiously waiting…

After getting hit by a truck in an attempt to chase down his brother's bullies, Alex in transmigrated into the body of a weak mage in a fantasy world called Eldora.As expected, transmigration can never be complete without a golden finger! Shortly after waking up in his new body, Alex awakens the almighty path system.But that wasn't all, a more shocking discovery almost blew Alex's mind away.....System is crashing!! System is crashing!! System is crashing!!!![Due to the system breaking down, several perimeters of the system have been broken. Required exp for leveling up is now fixed, repeatable missions no longer have limits and can be completed continuously even when capped. Penalty function disabled, rewards for missions are now fixed].......Alex's system got broken and a lot of functions stopped working but this was a good thing because Alex can now level up continuously without anything to slow him down.......Armed with such a system, join Alex as he journeys to become the strongest mage in this new world and what his reaction would be after finding out the secret of his system and why it had broken!!

– Question: “What is scarier than the personal experience of transmigrating into a horror movie?”

Anonymous: “Transmigrating into a movie you’ve never seen before.”

– “Poor comment! There’s nothing scary about that!”

Anonymous reply: “You sure? Can you be sure your dad isn’t a murderer? Can you be certain your spouse isn’t out to kill you for insurance money? Can you even be certain there isn’t any hidden lethal weapon in your son’s lunchbox? The scariest thing is that you have never seen this movie before so, you have absolutely no idea of any ‘surprise’ that awaits you ahead!”

Hence, this novel is also called .

A line to sum it up: The female lead transmigrates into various movie adaptations of real stories, and conquers the audience.

- Description from Novelupdates