The Hidden Dungeon Only I Can Enter - Chapter 3

You take up a student career.

Student career upgrade to lv.7

Acquired skills: primary school knowledge, junior high school knowledge, high school knowledge.

You take the college entrance examination,

You got a perfect score.

Your basic occupation has been upgraded to lv.9, and the job transfer system has been activated.

You change jobs to become a scientist, you gain R&D skills

You use research and development skills to get space fortress construction technology

You use R&D skills to gain starship technology.

You are invincible.

- Description from novelbuddy

A girl who calls herself a demon appeared before a timid student named Fumio Kijima. The girl claims to be a campaign girl from the demon world and she gives him the ability to “summon a room” from nothing but thin air.

At first he doesn’t abuse his power and uses it as a convenient ability in his every day life. But one day he is bullied by his classmates under a false pretext and is made to suffer. In the past he would have wallowed in misery and cried himself to sleep, but now he had a power to call upon.

“I will make them regret it!”

Using his powers to summon his “room”, he begins his era of confinement and brainwashing to achieve his goals.

Forge unparalleled mechs with the ambition of old age, and use the galaxy as a knife to smash the edge of the empire.

His name is Ji Xinghe. When he was 65 years old, he went to Alien Battlefield to avenge his son.

The old man is standing on the ground, his ambition is a thousand miles away, the old man wears armor, and fights to the galaxy, the old man drags his sword, it is not for glory.

- Description from novelbuddy