In December 2021 humans are faced with an alien invasion and by January 2023 only 10% of humanity are alive and they are facing an enemy they never dreamed could exist how will humanity fare with this new threat

Kioshi Chinen is a 17 year old Senior in high school, he lives a miserable life. Living in an apartment with a sex-addicted roommate who constantly hires prostitutes. He goes to buy a manga from his friend who's a receptionist at a Gymspark store and that's the day his life changed. He now has encountered the mafia and now has to climb the ranks of the mafia to secure himself a successful future with the head of the mafia's daughter, Mizuki.