The Villains Need to Save the World? - Volume 1 Chapter 28: The Human Reinforcement Forces’ Peril

As long as the land is square, Yan Bicheng should divide the world into four parts.
The dark organization “Ruyimen” has abducted children for many years, trained them as assassin agents, and sent them to the families of various countries for use in order to collect a lot of secrets, and gradually extended their evil hands to the court.
Feng Xiaoya, the favored minister of the King of Yan, suffers from bone melting disease. She is unparalleled in her “sickness and beauty”. For some reason, she abandons the eleventh wife, Qiu Jiang, and puts her under house arrest in the mountains. Qiu Jiang, who has forgotten his past, fled alone on a stormy night. After several twists and turns, on the way back, he met Yi Fei, the third prince of Cheng who was in trouble in a foreign land.
One wants to regain memory, the other wants to regain the throne. The two people who are incompatible with each other walk side by side towards Cheng in a bloody storm… but they find that the Ruyi Gate, which has been entrenched in Chengjing for a hundred years like a poisonous snake, seems to have undergone an unknown shock… …
The situation of the Four Kingdoms is back, and there is only one goal – to eradicate the evil organization Ruyimen!
However, as Qiu Jiang’s memory slowly recovered, a unparalleled secret finally surfaced…
Mrs. Ruyi, who is it? There is another mystery behind Ji Ying’s death?
What is the purpose of this return journey after a narrow escape, and where does it go?

- Description from novelbuddy

I, an ordinary high school student, Kimizuka Kimihiko, who easily gets involved in things, was appointed to take care of mysterious attache cases by mysterious men in black suits. After meeting a beautiful angel-like detective girl, named Siesta in a hijacked plane, I became her assistant.

And from there–

[You deal with the beehive, and I’ll restrain the enemy.] [Don’t make plans that make me the victim.]

We had those kinds of foolish conversations, all while being completely broke every day and fought against . Even when there were hurricanes, the weather-beaten duo sleep past it. Sometimes when we saved money at a casino, we would jump around on the beds at a resort hotel, only to be broke again the next day. We would walk through deserts, traverse through jungles, conquer mountains, cross oceans– The great detective and her assistant would go through these dazzling adventures–

Until she died.

And this story starts from 1 year after that incident.

I’m the only one who’s left, but I carry on her remained wishes.

This story is far from over..

A man was transported to Ancient China and eventually became a servant of a declining household without a male heir. He utilized his wits and modern knowledge to help the household and eventually become trapped in the sea of political turmoils of the period.

- Description from Novelupdates

Sure, the world is ruined, but I’ll live my own way. Of course, luxuriously and gorgeously.