The anime “Otome Game no Hametsu Flag shika Nai Akuyaku Reijou ni Tensei shiteshimatta…” (Hamefura in short) uses an on-screen alphabet that at first looked like random scribbles, but by episode 4 enough clues were provided to extrapolate the meaning of most gyphs and all numbers:
The numbers use a simple decimal digit system. For the letters there appears to be only one case, and most are clearly mapping on the Latin alphabet, but 28 glyphs have appeared on screen, 4 of which have only appeared in random pseudo-text and could therefore not be positively identified.
The difficulty was that most of the on-screen text appears to be simple gibberish, with notable exceptions like the student list and Katarina’s fertilizer bag in episode 4, the snake encyclopedia in the episode 2 post-credits scene, and the book cover in the opening.
Fortunately the first three names on the student list in episode 4 are known (although misspelled) and the rest of the list appears to contain a number of English words. Thanks to this, the “student list” identified all numbers and the entire alphabet except for J, Q and X.
The fertilizer bag in episode 4 confirmed the alphabet mapping, but added no additional information:
We had to wait for episode 9 to positively identify ‘X’. There was never a ‘J’ or ‘Q’ in non-random text.
I numbered the unidentified glyphs for transcription purposes:
English letter frequencies suggested that ?1 would be Q and J would be ?6 or ?4, but given the text these appear in is random (or at least not English) this is very dubious evidence.
?5 appeared only once, and since it looks very much like a mirrored Z, I think it was a fluke rather than a separate character.
Most of ?6 appears in the “fancy” signboards and Katarina’s handwriting, which were probably hand-drawn by someone, so I believe that it’s probably just a badly/differently drawn “A”.
After episode 11, I noticed that unknown ?1 appears right next to “K” more often than to any other character. Assuming the gibberish texts are generated by random typing on a standard Hiragana keyboard, the frequency of adjacent characters suggests that ?1 is more likely to be ‘J’ rather than ‘Q’:
The other unknowns appear too infrequently to draw conclusions I think, but here are the adjacent characters to unknown ?4:
And unknown ?6:
Although this is inconclusive, based on this I will assume ?1 is ‘J’ and ‘Q’ is ?4.
Book cover from the opening:
Episode 2 post-credits scene:
I almost gave up on the pages in episode 8, since the first line was clearly gibberish, but then I noticed there are a couple of words mixed with nonsense:
Unfortunately this sheds no new light on any of the remaining mystery characters. Also, Hokkaido???
This other page, in episode 8 (in the library, just before Katarina starts hallucinating about sweets) seems to be a badly butchered version of Justin Bieber’s “Love Yourself”. It’s unfortunately full of misspellings. It apparently uses ‘X’ a lot in place of ‘Y’: “when you go into clubs using my name…if you like (the way you look) that much baby you should go and love yourself” etc.
Episode 9 includes our first evidence of ‘X’, as well as a lot of non-gibberish text for a change:
Note that the cards are signed Catalina Kraes:
And they seem to stick with this strange spelling for Geordo:
Also from episode 9 is Anna’s letter:
The rest of the text was undecipherable, probably random keystrokes:
Episode 6 adds some more texts, but unfortunately all seem to be gibberish again:
The pamphlet with accusations in episode 10 is too blurry, but I could make out that most of it appears to be gibberish again, except for the last paragraph and some words in the middle I could decipher.
Sophia’s book covers appear to be mostly nonsense except for the one about flower art: