MTL - Princess too Young, Prince too Old - Chapter 14 King of Gundam 6

Naofumi Iwatani, an uncharismatic Otaku who spends his days on games and manga, suddenly finds himself summoned to a parallel universe! He discovers he is one of four heroes equipped with legendary weapons and tasked with saving the world from its prophesied destruction.

As the Shield Hero, the weakest of the heroes, all is not as it seems. Naofumi is soon alone, penniless, and betrayed. With no one to turn to, and nowhere to run, he is left with only his shield. Now, Naofumi must rise to become the legendary Shield Hero and save the world!

Let’s fight! Go! Who am I afraid of with a chip that turns into a brain cell? ! Get promoted and get rich! The nest treasures are all mine!

- Description from novelbuddy

An Individual from Earth finds themselves in the Shinobi World, equipped with a Scientific System. From that moment, he delved into scientific research far ahead of its time.

In the age of the Great Liang Dynasty, the lives of the people were made convenient with steam-powered machines that run on a fuel named Violetstream Gold. Chang Geng, who lived in a small countryside village, shared a distant relationship with his mother while his stepfather was away most of the year round, and the only people he was close to were two little kids, the village teacher, and his yi fu – adoptive father. But his life was flipped upside down one day following the barbaric Man tribes’ invasion, and it turned out that his entire identity had been an illusion – not only was Chang Geng himself not the country boy he thought he was, but also his mother, his teacher, and even his beloved yi fu…