Up a backstreet in Shibuya's Udagawacho neighborhood, tucked in behind the Milky Way, Chelsea Hotel and Star Lounge live-music venues — an area tight with record stores — I'm on my way to a party crammed with style-conscious young folk in sweaters and berets, DJing against the backdrop of Roman Polanski's 1965 film "Repulsion." That's when I see the billboard.