Tomodachi no Imouto ga Ore ni Dake Uzai - Volume 1, Chapter 1: My friend’s little sister is only annoying towards me

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.

Will people be conscious when they die? Yes, because I have experienced it.

Are there really ghosts in this world? Yes, because I am.

After borrowing the weight to give birth, He found out that he has a beautiful wife, sleep, still not sleeping?

- Description from MTL

After the soldiers’ mercenary group where he used to work had been utterly destroyed, Loren, who survived the disaster, decided to walk the adventurer’s path as a way to make a living. However, for Loren who had no acquaintances and nothing but an empty pocket on him, receiving a single quest seemed like a faraway aim. So, as he was contemplating about what he should do next, another adventurer called out to him.

Yang Wei and Qi Xiao Yan had been married for a year and were unable to reach mutual understanding on many topics, except for one——divorce!

They didn’t know that there was still one more thing they also reached a strong, mutual understanding on——

Want to find your second spring?* In your dreams!

In short: Mr. Qi and Mrs. Qi end up happily remarrying each other.

*(idiom) try to fall in love again

- Description from Novelupdates