The Strongest Student of the Weakest Academy - Chapter 21: The Academy’s Competition (III)

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.

Hao Ren (literally means “good man”), as his Chinese name suggested, is a good man, and his ideal was to live a restful, comfortable life as a landlord. At least that was his plan before a couple of abnormal creatures rented his house.

On this land of real souls, with millions of different martial art institutions, there are so many strong fighters just like the trees in the forests.

Among all, a mediocre apprentice from one of the mediocre institutions suddenly became a martial art genius after a mysterious incident. Not only did he acquire a photographic memory and keen perception, but he had also come to discover that his ability to comprehend martial arts is astronomically good, which eventually made him an almost godly existence.

From the hot-blooded intense battles to the clashes between the top geniuses, Martial Arts is no longer limited to the mortal world, it reaches to a level that can do everything from controlling the oceans to flying up the sky and diving under the ground.

- Description from Novelupdates

Side story of Kyoukai Senjou no Horizon bundled with the first press release of the 1st, 3rd, 5th and 7th Blu-ray volumes of both seasons of anime.

This side story follows Asama, Kimi and Mitotsudaira aboard Musashi one year before the beginning of the main story, as Asama is considering to create a music band together with her two friends for the next festival in Aki, a territory under the governance of K.P.A. Italia.