It Turns Out, They Are the Protagonists - Chapter 167: Core Formation Achieved, Time to Harvest!

She was born into a powerful family of the nobility, a blue-blooded aristocrat as capable as any man. He rose from humble origins up the military ranks, an iron-blooded knight with high ambitions. A transaction for power severed her from her childhood sweetheart. A tardy encounter was the beginning of his and her vow to meet life and death under heaven, standing shoulder to shoulder.

Political intrigue, dynastic succession struggles. He trampled through it all in the toil of becoming emperor.

Old enmities became new disputes, concerning life and death of entire families. She entered once more into the palace, changing the entire political climate of their world.

Meeting once again, they had become strangers. The peach blossom were all fallen, no more than a golden age grown cold.

- Description from Novelupdates

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.

Landmines include but are not limited to: Sweet & naive bottom, a president story, logic is dead, slow-progressing romance, the protagonist’s name has too many character strokes, the names are hard to pronounce, too many gay characters…

- Description from novelupdates

Fate is weird. Of all the people in the world, why would it select me to send to a different world?

And what is it trying to do? Put up a show by giving me a system? But oh well, what do I care.

The previous owner of this body was a cripple and looked down on, but now I can slap their faces with my system.

Young masters? Get out of my way!

Princes? Geniuses? Oh please. I have a system. That does not mean anything to me.

I know that I am not the greatest. But fate gave me a cheat system, and I am not wasting it.

I am going to do whatever it takes to conquer this world. Fate forced me to do this. It isn’t my fault if I cause some ruin on the way.