Elf Tensei Kara no Cheat Kenkoku-ki - Chapter 18Book 1: -2: Calm Before the Storm

On the surface, he is the aloof and standoffish patriot whose sole purpose is to serve the nation. On the darker side, he is an invincible, powerful and mysterious man.

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.

In this world, there are people who are born to suffer. They have no home, no children, no relatives, and even die tragically at the end, just like Qin Xiangnuan, who carried her burdens alone. In her thirties, she is just a flower that bloomed only to wither in her declining years, and she also has nothing.There are also those who are born to enjoy blessings, possessing wealth, beauty, a capable husband, and smart, beautiful children, yet they still take someone else's life, just like Qin Xiangmei. Though being biological sisters, she plotted against her sister from childhood until her death.If it weren't for rebirth, Qin Xiangnuan would never have known that her half-sister, Qin Xiangmei, not only took away her father and her elder brother's life but also the only keepsake her mother had left for her, and even a tremendous opportunity.

From the age of 7, Qiao Qiao realised that her family wasn’t quite the same as her friends’ families.

Her father, dressed in all white, said, “Our girl should learn to cultivate immortality with me!”

Her mother, dressed in battle armor, said, “Our girl should train her body to protect herself!”

When discussing it, they decided to solve it with a duel outside.

Her brother secretly asked, “Qiao Qiao, do you want to be in the entertainment industry with me?”

Then, her brother was kicked out of the house by her parents. She prayed that he was okay out there. 

Qiao Qiao sighed. She was really worried about this family.

She silently collected mech building materials. There was no other way, if she learned how to use mechs, she would be able to get a good job. Unfortunately, her unreliable parents didn’t understand.

It seems like the burden of supporting this family was handed over to her.

- Description from Novelupdates