Under the Oak Tree - Chapter 269 -

High school student Mikoshiba Ryouma was summoned to a different world in the middle of a war. Sensing the malice from the one who summoned him (a summoner of the O’ltormea empire), he uses his martial arts to run away, killing important people of the empire during his escape. After the escape, he rescues two twin sisters from the hands of thieves. The sisters who can use magic, swear to serve him as subordinates. Thus, Ryouma begins his journey on the path of the supreme ruler.

Time flew by. Even though their graduation was a long time ago, after countless nights and passing through fleeting time, their story is still circulated around the quiet campus of University G. This story has many different versions, but there is one thing that everyone knows to be true. Back then, that ordinary girl betrayed the genius of the fine arts faculty and yet, his love for her still remained. For her, he nearly died in a fire. For her, he gave up his chance to study abroad. Years later when they meet again, he is successful with a new girlfriend in his arms and she is indifferent with a light and clear smile. However, unknown to anyone, her longing had begun long ago and even now flooded her thoughts…

- Description from Novelupdates

She fought in the Battle of Changping and witnessed the killing of hundreds of thousands. She once led the Qin Iron Calvary and battled against the Six Kingdoms. She has seen a third of the land and witnessed the breaking of mountains and rivers. The sound of a grand zither and the light of a great female emperor. A prosperous world that was forged on the battlefield. Yet, these two thousand years are forgotten from history.

- Description from Novelupdates