Hi folks,
This calligraphic [?] variant of U+640D is included in Unicode's IVD (Ideographic Variation Database), which is incorporated into the Hanazono fonts (in HanaMinA). So that's why/how it's there. Unfortunately, Adobe didn't include it in their Japan1 collection, so we won't find it in any Adobe fonts.
I've only recently re-entered the world in the last few weeks after a four-year hiatus, so I'm not up on the current state of things. Variant glyphs within Unicode fonts is a thing, however -- some of them have long existed in the Hiragino fonts that come with OS X. Adobe was another early adopter. But I don't remember how to access/display them (the variants), if I ever knew. Their use should, ultimately, be handled by software -- most users won't know how to use the IVSes (Ideographic Variation Sequences), if indeed that is what needs to happen here.
Jens has put together a workaround that should work well for Don, but it would be nice to know how these glyphs are *supposed* to work in a font like HanaMinA in the first place!
Anyone? If not, I'll see what I can learn. Note that 640D E0102 is the correct IVS for the variant. Adobe used 640D E0100 for the base character in Japan1 and 640D E0101 is used for the base character in Moji Joho.
Eric