I don't recall too many kayo kyoku singers wearing hats while performing, but I still have to say that no one wore one as well as Kenji Sawada（沢田研二）. There was something about that rakish angle just above those droopy eyes that just screamed "JULIE!" I've often equated Sawada with David Bowie, and the former's appearance back in the late 70s may have hinted (unintentionally) at the fashion that the latter would adopt a few years later.
My other international pop cultural example of cross-pollination with Sawada is about this song itself. I vaguely recollect Woody Allen's tribute to Humphrey Bogart via his 1972 film, "Play It Again, Sam", and I often get reminded of this particular movie when Sawada does his own tribute to the legendary star of the Golden Age of Hollywood through "Casablanca Dandy", his 26th single from February 1979.
The video above has Sawada at his hedonistic best (and true to the title) as he struts and slinks in the studio and howls his admiration for Bogie through Yu Aku's（阿久悠） lyrics (the yelling of Bogart's nickname in the refrain is the part I remember the most). I'm not quite sure whether the actor would've have liked the down-n'-dirty rock by Katsuo Ono（大野克夫）but then again if the actor had been born several decades later than he had been and then entered Hollywood, rock could've been the accompanying genre for him. Speaking of which, the accompanying group backing him up on the recording was the Takayuki Inoue Band（井上堯之バンド）.
And certainly true to the devil-may-care attitude espoused by Bogart, Julie probably had a lot of fans and others gabbing when he took a swig of the good stuff at one performance and just sprayed it out like a whale's blowhole. However, he later stated his regret at the act when he found out that little kids were emulating him. Sawada may have shown a punk attitude at the time but I don't think Sid Vicious needed to have worried too much.
"Casablanca Dandy" peaked at No. 5 on Oricon and became the 26th-ranked single of the year. It also earned the Gold Prize at the Japan Record Awards.