The character makes a pact with the devil in order to take revenge on society. Adding to that, you get to play past incarnations of the main character at some points. Like many of these weird indie games, it's confusing, rebellious, malicious and extremely creative.
And also very janky. It uses real time combat in rpg maker engine which is definitely not meant for it and also large sprites that don't have proper hitbox support. It's probably quite hard for the average player to get into it, but personally it's one of my favorite games.