MTL - Life Simulation: Propose Marriage To Kushina Uzumaki at the Beginning of the Game - Chapter 3

A world only I know of, now I will take it all for myself.There’s no kind soul here willing to share and eat nicely with others.Only the ruthless one who will devour it all alone exists here.

“Sect Master Uncle is just a mortal, who just happens to have his own ‘billion’ interpretations of various spells.”Atop Misty Peak, the sect’s senior disciple was educating the new beginners.At that moment, Sect Leader Ye Feng, holding a blade of grass, waved it gently, and a fierce Sword Qi split the sky in two, revealing a dark spatial rift that was difficult to heal, frightening the gods above.The new disciple pointed at the sky, shocked, “And you told me the Sect Leader is just a mortal?”

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.

Waking up again in his seventh reincarnation, prince Jing Beiyuan found himself back in time, when everything had yet to be set in motion. Having been given a second chance, Beiyuan had to survive court and decide whether it was finally time for him to let go of his feelings; all while trying to handle the youthful, innocent force of nature who had suddenly barged into his already complicated life.

- Description from Novelupdates