My Mr. Song is extremely protective ( Machine Translation ) - Chapter 6 - Chapter six, borrowing Mixiu

A man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his rigorous discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life. This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.

A side story series featuring the girls of Kyoukai Senjou no Horizon.

The female protagonist of this book is a zombie (probably!) The male protagonist of this book is an air (maybe, but you can’t see it?) The system of this book is a bastard (like to open a mouth too much?) Anyway, this is a story about zombie with a memory, going back to the past, but accidentally turning this book into a story of a savior! (Huh? What? There is a killer? No, believe the author, she really did not kill, really! (No wonder!)

The heroine said: The title of the book and so on are all fake!

- Description from Novelupdates