The first time that I heard this really cookin' tune by singer-songwriter Mami Ayukawa（鮎川麻弥）, I figured that "Sleep Walker" was a City Pop tune concocted around the late 1980s or early 1990s. And sure enough, it's the lead track on Ayukawa's 9th original album "Hyakku-Ichiban-me no Koi"（101番目の恋...Hundred and First Love）, released in November 1990.
Written and composed by the singer and arranged by Akira Inoue（井上鑑）, the cool thrumming of one synth, the champagne keyboards and the percolating percussion simply make "Sleep Walker" a most appropriate tune to accompany a financially fine time in downtown Tokyo. It's also a most ironically titled one as well, since I can't imagine anyone sleep walking to this, unless the meaning is that the tune is so catchy that even people in bed can't help but strut outside for a very late night out on the town. There's very much of a sophisticated pop sound to this one....gotta have a glass of the Perrier-Jouët Champagne Blanc de Blancs Brut (heard that was one of the top champagnes for 2019) while listening.