Author's Reincarnation in a Fantasy Setting - Chapter 231 Island [5]

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.

On his usual way to home Mikado Tsuchio fell into a hole that suddenly opened on the ground. Just like that, Tsuchio falls in a different world, he lands on a Grappler Wyvern and manages to tame it.

Tsuchio decides just like that to live in the other world, the reason for his quick decision: he wants to make a monster girl harem.

Once time travelling, the talented young master became the idiot of the Gu family who was cut open and her son was taken away by others. Five years later, she came back with a cute baby. – She did it! Expensive jewelry that is popular in Beijing——she designed it!

The top restaurants all over the mainland – she opened it!

Even the most mysterious island of no return is hers!

Miss Gu took her son to eat and drink spicy food, slapped his face and watched the show, so happy!

But one day, a certain man suddenly blocked her door: “Woman, how dare you steal my prince’s son!”

Ha! Want to snatch her son? “Close the door and let the dogs go!”

- Description from novelbuddy

The most successful businessman of his time, who started from being a homeless orphan, died indignantly because of being plotted against by his most trusted aid, his own brother.