Divine Luck: SSS-Rank Battle Maid Harem - Chapter 557: Satisfied?

Jiang Pengji got something called the Court Intrigue Stream System.
System: “Your goal is to become the most prestigious woman in the kingdom (the Queen)!”
Jiang Pengji: “Okay, System. No problem!”
Years later, she met the target by becoming the most prestigious woman (the Empress).
Jiang Pengji: “Well done, no?”

- Description from Novelupdates

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.

One day, I – a high schooler – found a paperback in the hospital. The “Disease Coexistence Journal” was its title. It was a diary that my classmate, Sakura Yamauchi, had written in secret. Inside, it was written that due to her pancreatic disease, her days were numbered. And thus, I coincidentally went from Just-a-Classmate to a Secret-Knowing-Classmate. It was as if I were being drawn to her, who was my polar opposite. However, the world presented the girl that was already suffering from an illness with an equally cruel reality…

The best-selling, award-winning debut work by Yoru Sumino:

“Bestsellers 2016 (Overall) by NIPPAN” – 4th Place

“Bestsellers 2016 (Paperback Fiction) by NIPPAN” – 1st Place

“Bestsellers 2016 (Overall) by TOHAN” – 5th Place

“Bestsellers 2016 (Literary Books) by TOHAN” – 1st Place

“Bookstore Grand Prix 2016” – 2nd Place

“DA VINCI BOOK OF THE YEAR 2015” – 2nd Place

“Bestsellers 2015 (Literary Books) by TOHAN” – 6th Place

As of May 2017, this book has sold over 1.2 million copies.