They are girls from 21 to 18 years of age.
The most normal of them its a neurotic, controlling perfectionist with mental powers that works part-time as a private military and is struggling with a literal space spirit of destruction taking over her mind.
Youre lucky they arent even worse off.
Look, I get that you and others see things form a comic accurate perspective. But from a gameplay perspective, they're just arbitrary limitations that hold back the jealously/cheating system from reaching it's full potential. For the past year or so since it's been implemented, it still feels binary: Either you
only talk to one girl, and study, train, swim, etcetera with the other two merely for either story progression or building the harem - because talking still counts as flirting and thus still summons Rogue's, Jean's or Laura's wrath - or everyone joins the harem; which isn't how I'd personally want to play the game outside of experimentation and memes.
Basically, RLE's "talk" option in this game would go a long way with me for making the social sim aspects feel less limited. Adding in dialogue options such as "It's not like that. We're just friends." or intentionally being a dirtbag by saying "Yeah, I want her too. Deal with it." or "She's prettier than you." would flush things out further. Or in other words: Why be the original Persona 3 when you can be Persona 4, 5 and 3 Reload?
