Mother of Learning - Chapter 21

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 previous life, I was just a mediocre guy, and accomplished nothing.

After reincarnation, I seize the opportunity of being a legend of the times. In this life, I am the protagonist in Tianxuan World, a great master of martial arts and a founder of making elixirs. What? You want to compete with me in weapon and equipment refining? Then, you should know the Craft God is my disciple…

- Description from Novelupdates

Finding an ancient treasure was not as fortunate as one might expect. As soon as Bai Rouyun had left the grave, countless sects and hidden families set out to kill her for the sake of obtaining her treasure for themselves.

Tang was cheated by her husband who got another woman pregnant. Tricked by the mistress and mother-in-law, she had been criticized by the public and kicked out of her husband’s family. Then, there comes Su, who showed up like a saviour for her, prevented her from all the difficulties that her ex’s family made to her. He held her in his arms, haughtily said to them, ‘It will only be me that can bully my girl! Anyone who dares to bully her is opposing me!’ She was shocked. And her mother-in-law said she was a wanton woman. After that, he was always protecting her, treated her preciously. He made her realized that even the second marriage could also make her so happy!

- Description from Novelupdates