Upside down! I can't really even wrap my head around that one, but I'll take your word for it (and the results look great)! But wow... I did a quick Google on those Naginata nibs and they seem to be quite a bit out of my price range
If you want to have a taste of a nib with that kind of capability for about US$20, you can try a Hero 187 with a Fude nib. For some reason, a search for that tosses up some pens that look like the one I got, and some that don't, so be careful.
The Fude nib is essentially a physically inverted Concord nib. Sailor makes three models of cheap pens with Fude nibs (two with the bird beak bent at 55°, and one at 40°), but the nibs are pretty bad on those and not even a close imitation of the Naginata Fude de Mannen nib or its sibling the Naginata Concord nib. The Fude nib on the Hero 187 is actually OK, but a bit too wet for my tastes.
Here's another fun nib with some pretty broad capabilities:
Edited by A Smug Dill, 29 January 2019 - 04:20.