Many JRPGs characters are designed weirdly and outstanding, but that wasn’t always like this. Years before JRPGs grew from all that western-style creativity, as Dungeons & Dragons, which included large amount of knights in armor. The Final Fantasy franchise changed this state of affairs, and we should thank a character designer Yoshitaka Amano for that.
Amano’s artwork has a long way of transformations, starting with Art Nouveau and coming to ukiyo-e, the Edo period style of Japanese woodblock printing. The ukiyo-e characters are usually highly noticeable figures like kabuki actors or geishas. Hair and cloth style were an important part of everything — that’s what Amano was based on while creating his arts.
Talking about Amano’s successor, Tetsuya Nomura, he takes his inspiration from streetwear fashion. Streetwear was a notable style in Japan in the 1980s, developing more of them like Lolita or body-con each year. Also there’s the influence of eminent designers, like Rei Kawakubo and Vivienne Westwood, if you look at the Final Fantasy characters design.