Strange Life of a Cat - Chapter 106: My Whiskers!

Years ago, Earth was indoctrinated into the “System.”Earth was not the only place with the System, however. With the System came the other races, Invaders. The Invaders had one goal, to obtain ownership of this new habitable planet. This created a bloodbath, and for years the war raged.This didn't really have much to do with Derek. Derek was kind of a loner. Yeah, he enjoyed the occasional chat or drink with others, but he never stayed in one place too long or really got to know anybody new.Derek did happen to be rather strong. After the years of fighting monster and Invaders alone, he had become quite adept at surviving. One thing that helped keep him alive was his refusal to get involved with others. He rarely cooperated with teams.One day, Derek broke his rules and decided to lend some help, as the mission didn't seem too hard. He should have stuck to being alone.

A tree of 10,000 flowers, the world is the door.
The spells change a lot, but the hearts of the people are unchanged.

- Description from Uukanshu translation

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.