Sukajan (スカジャン) are colorful jackets with embroidered designs on the back—much like Gosling's threads. Young blue-collar characters in Japanese manga, anime, and video games are often seen sporting the sukajan. Sukajan are very much Japanese—yet their American roots and influence are undeniable.
The jumpers appeared in Japan during the Post War Occupation. American troops began getting Japanese designs sewed into their jackets. During the years following the war, U.S. military fashion was popular in Japan as were G.I. style crew cuts. The look caught on with the locals.
The origin of the "sukajan" moniker is a bit of a mystery. The name could come from the word "Sky Dragon", those flying dragons you see in Japanese art and popular culture. Early on, the design was popular for the jumpers, which is why in Japanese, a language that loves to shorten words, "sky dragon jumper" (スカイドラゴンジャンパー) became "sukajan". There's another theory that the name comes from "Yokosuka jumper" (横須賀ジャンパー), which was shortened to "sukajan". Yokosuka was, of course, the home to a U.S. military base and the birthplace of these jackets.
Even today, the jackets reek Showa Era Japan. By the 1960s, the preppy "Ivy Look" was in with teens. The sukajan, however, became standard for tough rebels without causes.
The jacket carried blue-collar juvenile delinquent connotations. Young wannabe yakuza hoods have donned in the past. The connotations exist today, but many young Japanese hipsters wear the sukajan with a hint of irony, just like Americans ironically wore trucker hats. So just because someone is wearing one of these, it doesn't mean they've done time in juvey. They're part of the culture that sprung up in Post War Japan.
For those visiting Kanagawa, Japan, the jackets are popular souvenirs. Kanagawa's Okuma Shoukai, which outfitted idols AKB48 in sukajan for a TV drama, is the sukajan retailer. Check out its wearable wares here.