Genius Doctor Black Belly Miss - Chapter 11

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.

Feng Ming was only 19 when he lost his life saving a child from death without hesitation. The grateful father of the rescued child grants Feng Ming a second chance at life. Unknown to Feng Ming, his soul has whisked away to a far away ancient land (resembling the dynasties of China).

drop out of school

When I got home, I reopened the blacksmith shop.

From then on, this blacksmith shop was no longer ordinary.

The best knives in the world are born here.

The thrust-to-weight ratio of the handmade micro-turbojet directly exploded.

The micro-drones flourished in his hands.

- Description from novelbuddy

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!