The Gakken Analog Synthesizer SX-150 is a single oscillator analog synthesizer that comes bundled with a special issue of Gakken Otona No Kagaku - a Japanese science magazine available via the Otona No Kagaku shop, amazon.co.jp and ebay. There seems to be a lack of English documentation for the SX-150 (technabob and microscopics have a bit) so I'm gonna give it my best to provide as much information as possible in that I see a mild obsession coming on. So far I've taken a couple photographs of the first moments with the SX-150 and a couple (crappy) scans from the magazine included (really just the pages that describe some of the interesting modifications that have been made to the SX-150).

On a side note, YMCK has a little article in the magazine! Haven't gotten around to reading it yet but I'll let you know...