The context missing from a lot of the debate here is that it isn't just the protagonists who are psychotic assholes, it's a lot of the characters, including the other pair of girls and the boyfriends, and also most of the entire city.
Not just because we, the player, observe that we're playing a brawler where we are getting in non-stop street-fights for 10 hours straight, with people who are attacking us on sight for no discernible reason, but because that's actually addressed explicitly in the dialogue. Before you get to the third boss, Ryoko straight-up asks Misako what's up with this town, where everyone is a psychopath that can't have an interaction with another person without it turning violent.
The whole game is written about a giant clusterfuck of a city, filled with terrible, violent people.
Some people in this thread are talking about the protagonist like they were virtuous heroes up until one plot twist at the very end, but at no point in the game are they characterized as good people. Play it again, and actually take the story in.
Every 10 minutes you're getting one of the girls making some comment about destroying property without justification, or escalating simple situations straight to violence.
Before you even get to the second boss, you meet a character Misako doesn't recognize at first, then she remembers she used to beat him up and take his lunch money. That's very early in the game.
Were people paying attention to any of the writing before the ending?
The game even opens with the girls in detention. The very first thing the game tells you about them, before you even take control of a character, is that these girls are trouble.