Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Volume 17 Chapter 39

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.

Unhindered in the Demon Domain, the king is solitary!

In the world where immortals and demons strive, a good natured fellow sought the Demon Dao in search of justice.

At the end of his journey, he had eventually become this generation’s Heavenly Demon Emperor.

Although I am not fond of slaughter, I do not dislike it!

Desiring to see the Demon World, this is how I strive, this is how I become the Peerless Demonic Lord!

- Description from Novelupdates

After being set up and killed by her half-sister whom her ex-boyfriend had cheated with, Mu Siyin woke up one day to discover that not only was she alive, but she had traveled back in time to 2 years before her death.

Western VRMMO【DEMONDAL】was known for its extremely harsh game system. To begin with, there were no levels. There were no skills. There were no guilds. There was no inventory. There were no convenient system messages or maps of any kind either. It was so needlessly realistic that it was already basically a VR life simulator.

As for anything game-like, it was basically limited to weapon masteries; a proficiency level that you got from using your weapon, as well as physical strength that increased as well. That was it.

It was a fantasy game so there was magic, but forming a contract with a spirit was extremely difficult, and only 1% of the playerbase were magicians.

In this VR game【DEMONDAL】that was ridiculously close to reality, the protagonist Kei who was a well known mounted archery expert, was one day sent to another world with his Russian【DEMONDAL】friend.

The game that was severe to begin with had turned into a reality, and the harshness increased again――