MTL - After Being Transported into a Book, I Adopted the Villain - Chapter 20

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.

Young Master He had always been a male god in the eyes of others.

Being able to learn any skill immediately, and just by raising its proficiency, stand at the summit.

He is the World Chef Association Honorary Chairman, having the title of the World Chef God.

He is the greatest composer, pianist, and conductor after Beethoven and Mozart.

He also has the title of Underground Racing King, Fist King, Gambling King, Giant of the Stock Exchange Market, Arm of the Industries and King of the Skies.

He who has a miraculous learning ability and can stand at the apex of all things if he so wishes for it, the Omni Genius.

- Description from Novelupdates

At age 5, Amon unlocks the unique «Fury» genetics and is what caused his behavior to change.

After living with his grandparents for 11 years he learned to behave. For reasons he can’t know, his grandparents faked their deaths, and now he needed to move.

Now he would have to face a new challenge which was to live with his mother and stepfather and two twin sisters not linked by blood and go to school.