My Core is the Boss - Chapter 171.1: Kill the New God, Hold a Feast

A series of short stories in the world of Toaru Majutsu no Index organized into chapters featuring Kanzaki Kaori as the protagonist, going around the world and space doing missions for the Church of Necessary Evil, however, there is more than meets the eye as each incident is connected.

One chapter was bundled with each limited edition release of the Toaru Kagaku no Railgun anime DVD and BDs, with all of them together being equivalent to a single normal Toaru Majutsu no Index volume

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.

Kurono Maou is a high school student who is sensitive of his sharp eyes and bad expression. No girlfriend but gifted with friends in his own way, he had been living a peaceful life.

Existence was divided into three realms. The Heavenly Realm. The Earthen Realm. The Infernal Realm. Below them, countless minor realms of all types existed, none able to match the might of any of the Three Fundamental realms. The Celestials led the Heavenly Realm, The Immortals led the Earthen Realm and Demons led the Infernal Realm while the Rulers controlled all the minor realms. Together, they formed The Myriad Unity and allowed peace to reign supreme. The mortals were allowed to cultivate and reach for the Heavens as a balance was installed between the Heaven and Earth, all according to the Heaven’s Will. And yet, among the billions of trillions of living beings within the Myriad Unity, one seemed unsatisfied. “They are lying to us.” This man went against all known truths and contradicted the very gods. “We are in a false world! Mere pawns used to study an outcome!” And so in search of freedom and truth, this man committed the ultimate taboo. He rebelled.