Apocalypse Chaos - I am the villain - Chapter 163 Akiko’s Thinking

The main character Lei Yu does not have the ability to practice his family’s martial arts. He gets stepped on and tossed around. Due to certain reasons, he leaves the family, coincidentally gains an ability, and makes his own path to becoming an immortal.

- 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.

As his contract-marriage wife, she just wanted to fulfill the mission given by his mother—having a baby. They didn't love each other, so he always used contraception before they got laid. She had been obedient to him, only to find that he had gone too far! He actually didn't care about their child at all! She couldn't stand it anymore, so she handed him the divorce papers and left, noting: “The world is so huge that I can surely find a better man.”Looking down at her, he retorted, “Come on, your purse strings will tighten up first before you find anyone.”

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.