It looks very similar to an Excalibur. If you search “Excalibur” on this site, you’ll find questions and comments about them. The US sellers of Excaliburs have in the past given the impression (which apparently is false) that they are hand crafted in the USA.
It looks similar to this model: http://www.jimlaabsmusic.com/melodicas/excalibur-37-note-pro-artist-series-melodica-black/prod_802.html
Young Chang is, of course, a respectable maker of pianos (and I think of Kurzweil keyboards). Some Chinese made melodicas are marketed (on eBay) under under the Yamaha name that do not appear to be Yamahas. I would be surprised if this instrument was actually from Young Chang the piano maker. The term “melodion” is, I believe, owned and usually only used by Suzuki, but it doesn’t look like a Suzuki. None of which means that it’s not fun to play or doesn’t produce good sound.