The Persona Series is based on the Jungian psychology, stuff like Persona, Shadow, Philemon etc, so that naturally got me (and lots of other Persona fans) into reading his Books and articles...and Man this guy's a Beast! I've been Reading his "undiscovered Self" and I highly Recommend it.it's a really amazing book, its about people tied to the limits of society and stuff like that.
sounds familiar?! yep, persona 5! "The story of Persona 5 will discuss the hardships of modern day society and feature characters that are restrained by the rules set by this society", as Katsura Hashino, the producer of the Persona series stated back then.
they Probably got the Idea from this book, therefore i guess it is wise to read it before playing P5, so we may notice the references and it helps us understand the whole concept better.
But I'd Still recommend it even if you are not a Persona fan, because it makes some really good points about the current state of the World and helps you realize some overlooked aspects of your life and gives some insights, So give it a Shot.
P.S it's actually a Hard book to read, for someone who's hasn't read anything beside teen fantasy novels it was really hard to understand at first, but its really Worth it!