In the mid-1980s, Toshiba's industrial designers were apparently tasked with designing a Walkman that would be smaller than everyone else's—in just one dimension, that is. They then came up with the KT-AS10, a/k/a the Walky:
That said, the unit doesn't look fun to use. Here's a demo video shot by someone selling one on eBay, to prove it works:
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Funny thing: This video is at least partially faked. Watch closely around 1:19, and you'll spot a jump in the video—look at the top of the cassette—yet the music continues uninterrupted. I hope whomever bought it on eBay didn't get screwed.
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