Chaos Devourer System - Chapter 563: Ancient Tomes...

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.

Nate, a transmigrator from Earth, arrived in the anime world of Fairy Tail!He acquired a magic called “Internet!” He developed it and got everyone hooked!You can livestream, chat, and even... hmm? Find girls to date!Sasuga Nate-san, Internet Magic is the best!

The Empress who dies in torture, An Rushuang is her name. After she wakes up, she finds herself has time-travelled to when she was twelve years old, but she would turn into Major General’s white horse at night. He is a general who orders about the winds and clouds on the battlefield, and she is a little girl lives in her boudoir seclusively.
She endeavors to change her fate, and he spared no effort to win every battle. They meet each other every day, well, it’s night to be accurate. Is that a dream or not? She pleads to marry the seignior to win peace for her family, only to find he is the one she is going to marry.
“Growing old with you under the same roof is my long-cherished wish”, thought them both.

- Description from Novelupdates

Reborn into the world of Yugioh, it's natural if my goal is to become the best duelist!