in that interview where we saw the original p3 social link planning things, hashino goes on to talk about p4 and its story and the influences. he specifically talks about kindaichi and how the idea for p4 was "small city" + "kindaichi". hashino has spoken about kindaichi in relation to p4 before, but this interview, i think he gave more detail about what he meant by that.
kindaichi is a series of older japanese mystery novels by yokomizo about a fictional detective named kindaichi. later, there was an unrelated but claimed to be related manga, the kindaichi case files, not by yokomizo, but the premise was the main character is possibly a descendant of the original detective kindaichi. chie even has a line where she likens naoto to kindaichi as being part of a family with multiple generations of detectives (which was changed in eng to reference raido kuzunoha instead cause americans wouldn't know kindaichi lol).
hashino recalls reading a critique of kindaichi. and, based on this critique, he proceeds to describe this kinda caricature of how a typical kindaichi novel goes: city boy kindaichi is called to a smaller city / rural area. he is an outsider who is new to the town, doesn't know anything about the townspeople, their customs, etc. he causes chaos by pointing out who the culprit is, then the culprit goes, "grr! welp guess i'll just die now", then kindaichi is like "well shucks the culprit just leapt to their death sorry lol anyway bye back to the big city for me".
hashino likens this process to kindaichi destroying things - kindaichi represents the new/urban element, and he goes to an old/traditional city, and he fucks everything up. hashino then adds his personal interpretation that yokomizo used this fictional mystery / entertainment structure as a like... narrative framework...? for how a lot of prewar / traditional / longstanding things got broken down in the postwar era. like kindaichi is removing a jenga piece and everything just collapses afterwards.
so in the past, when hashino talked about kindaichi, i thought he was talking about being inspired by like... the general idea of kindaichi? like maybe you read sherlock holmes or nancy drew or something, so you think of that inspiring you when you get to make your own mystery? but what hashino says here, it sounds like criticism he read of kindaichi was a bigger influence on p4 than actual kindaichi lol.....
like after reading his thoughts on this, i think you can easily correlate multiple things in p4 to being relevant to or possibly influenced by hashino's views on kindaichi as this "old vs new" kind of thing.
for example, there's junes vs the shopping street, in the sense that it's "the old vs the new". junes is this "invader" to inaba's traditional shopping street. and then as the game goes on and the fog appears, some npcs even mention the fog being some kind of conspiracy from junes. maybe that's like, the towns people viewing the fog and junes as their version of the destruction caused by kindaichi?
the protagonist, while he is not called to inaba to solve the murder as kindaichi would, feels like an... "anti-kindaichi". he makes friends with people in inaba and he forms social links, he fully integrates himself into inaba, and doesn't just get on the train and leave with everything gone to shit. and amongst his friends are these characters who have connections to "old" and "new" elements: you have yukiko and kanji and rise, whose families own businesses that represent the traditional side of inaba. then you have yosuke + teddie who are associated with junes, and naoto who comes off as a played straight kindaichi at first.
naoto... really does seem like this almost-played-straight version of kindaichi, and then rise is the one who voices criticism of naoto similar to what hashino read about kindaichi. but then, by the end, naoto is clearly not just this... invasive species of detective who comes there and leaves everything in shambles lol. recall what naoto says to the protagonist in the ending - she talks about getting on the train and going back to the big city with him, but she resolves to stay and see the aftermath through, like a counter to hashino's view of kindaichi as causing destruction and leaving asap.
i think adachi can also be viewed under this "hashino's recollection of criticism of kindaichi" as well. compared to the protag being the "anti-kindaichi" and naoto being the "half kindaichi", then i guess adachi might qualify as the closest thing p4 has to an actual kindaichi figure? he is a detective from the big city, and he doesn't seem to try and integrate himself into the culture of inaba. and due to him being the murderer, he is also the destructive, invasive element that turns inaba on its head. (i am under the impression that kindaichi himself doesn't show contempt for the settings he visits, so perhaps adachi is more of a caricature lol) however, through the power of like, anime and friendship or something, inaba avoids being destroyed
and, if we view adachi this way, then perhaps we can take his role in the story, and reflect it back to the kindaichi novels? hashino is, by extension, suggesting that kindaichi, who leaves destruction where he goes by exposing the culprit and tearing down these traditions, has also committed a type of "murder"
izanami also feels connected to this idea: she intentionally tries to introduce outsiders to inaba to mix things up, perhaps positioning her more similar to the role of the author, yokomizo, who sticks kindaichi in these situations to begin with lol
while this might feels a bit mild or something, the conclusion the game seems to land on is, "why cant the old and new co-exist?" unlike hashino's interpretation of "kindaichi represents tearing up the foundations of set in prewar japan", we dont get the idea that inaba has been completely devestated by this. like, the amagi inn doesn't explode because mayumi was murdered there, and in golden, we learn that junes has started carrying products from the central shopping district.
