If it had been anyone else I might have had a hope of tracking it down, but this is a man who is well documented to entertain style from the full spectrum of brands and affordability. This scarf could be £20 from Uniqlo or £2k from Balenciaga.
One thing I do know is that it isn't any of the brands I would usually favour, which rules out most of Japan.
Whatever. The hunt is on.
