Blood Titan System - Chapter 9 The Prodigy, Leah Astria

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.

As a walk-on, he had been the mistress of his sugar daddy for three year. However, they only had met each other for a few times.
As a boss, his sugar daddy had tons of lovers.
The walk-on: The cake shop is the only thing I love in this world. Lovers? Never want one.
The boss: No problem. Nobody wants that.
Then, they fell in love with each other…
Shameless playboy x heartless rogue
1v1, this is not a decent love novel.

- Description from Novelupdates

“Welcome to the Cosmos of Madness!”

Said a man with long red hair and piercing golden eyes as he descended from the stars.

“You have been chosen for a great purpose! Task! Mission! Destiny!”

He shouted dramatically as countless worlds heard his every word, from the lowest peasants to the mighty entities in the lofty palaces in the Higher Dimension.

“All of you accept your destiny as a sacrifice to Daemon Sultan, Blind Idiot God, Primordial Demiurge, Azathoth!”

And then Apocalypse descended.

***

Follow the journey of self-named Samiel Zentaur, a half-mad worshipper of the Outer Gods, on the Path of Transcendence and in his path to find himself.

A generation of hegemons, betrayed by betrayal, besieged by forty-nine strong men, tragically killed and robbed the mountain, re-lived once, he will re-enter the peak; strong rise, into the chaotic star field, exhausted 100,000 strong, Wusheng dead and kill, The impact is high!

- Description from 69shu translation