Wow, that is very much trying to mimic the feel of Illuminated letters
. Since they are only used for the first letter of a word, it's usually not that difficult to figure out what it is even with highly ornate Illuminated letters.
I think a more accurate description would be Fraktur script.
I don't have a problem making out the letters in English (or the Latin/Roman alphabet specifically). But the point here is that I'm so accustomed to a lifetime of only ever
seeing these letters specifically used for the Latin alphabet. And as they are generally slightly challenging to make out, my brain seems to have become accustomed to shifting into a specific mode where it tries to see the general shapes of the Latin alphabet when it sees this particular type of script.
But because there are actually no Latin letters here, but rather katakana... my brain doesn't find the patterns it expects to find, and has a little trouble switching to try to see katakana in the same way.
Even with some other unique and out of the ordinary katakana fonts, I can still fairly easily make them out.
But with the Goura font (the Fraktur one), given the particular type of script used, my brain specifically strongly expects something it does not find.
For instance I could glance at a page like that of English (Latin/Roman) letters and much more readily make out several of them at a glance. Here I have to focus on each one and make it out one at a time.