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 a clue was provided that allows us 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 so far 28 glyphs have appeared, 5 of which I have not yet been able to identify.
I numbered the unidentified glyphs for transcription purposes. Among the unidentified glyphs, ?1 appeared 8 times, ?2 and ?4 appeared 6 times each, ?5 once and ?6 twice, in the texts I transcribed so far. English letter frequencies suggest that ?1 would be X and Q would be ?2 or ?4, but given the text these appear in is random or at least not English this is very dubious evidence. If we assume that Q would resemble O and J would resemble I, ?2 is probably Q and ?6 is probably J. ?5 looks very much like a mirrored Z and since it appeared only once, it might be a fluke. Or the surplus glyph(s) could be symbols like & or such.
The difficulty is that most of the on-screen text appears to be simple gibberish, with the exception of the student list and Katarina’s fertilizer bag in episode 4, and the book cover in the opening.
Fortunately the first three names on the student list are known (although misspelled) and the rest of the list appears to contain a number of English words. Only one of the unidentified glyphs appears on the student list and is not part of a word.
The fertilizer bag in episode 4 confirms the alphabet mapping, but adds no additional information:
It will be interesting to see if more intelligible test will appear that will allow us to map the rest of the alphabet.
EDIT: I almost gave up on the pages in episode 7, 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???
The rest of the text so far was undecipherable, probably random keystrokes:
Episode 6 adds some more texts, but unfortunately all seem to be gibberish again:
Episode 6 only confirms that all mystery characters, except for ?5 (the mirrored Z), continue to be used.