Dafeng Night Watchman - Chapter 23 - : The Ministry of Justice Arrests the Criminal

The dawn era after the end of the half century has gradually rebuilt the order, abandoned civilization, and is full of undivided violence and desire.
The noble and powerful pioneers are in charge of the city, and the evil and mad plagues are in the wilderness.
Pure human beings who cannot mutate are the weakest, dominated by the rulers of the pioneers, and are not as good as animals in the wilderness.
A purely humanized young man with a worldly experience has quietly entered the WTO, holding a three-foot long knife and a long-distance desire to boil in the world of purgatory. From the nameless name to the sorrow of the Supreme Court, the name of the black ride is resounding!

- Description from Uukanshu (translated)

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 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.

I was forced to live in captivity for the rest of my life because I happened to be aware of the fact that I was a saint. I was truly a ‘real’ saint, but that didn’t matter, because there was already a designated saint in the temple.

When I died from all the abuse I endured, I was sent back to a time before all those previous events in my life had happened. After 15 regressions, I was exhausted. I prayed, “I don’t want anything to do with this, so please just let me die,”

And at that moment when I could finally be able to die, someone said, “How about being my daughter?”

…. That monstrous duke had adopted me.