OT: Need professional help for “definition” JDM

Definition may be the wrong word, but I think there’s still the most idea of it here, unlike the other forums… What exactly does it mean for you when a vehicle is made in the JDM style in tuning? I’m interested in it because I’ve heard and read so much about it now, but I can’t imagine exactly what the “art” is about… And because an acquaintance thinks what he’s doing with his EJ6 coupé would be JDM… (17″ chrome rims, spoiler lips, other thresholdrs, Altezzas, projector headlights)