This seems unlikely. The pronunciation was tsu before WWII. But the organization of the syllabary strongly suggests that the pronunciation was once tu.
I don't know to what degree the syllable 'tu' is viewed as impossible in Japanese as opposed to merely nonexistent. (Compare Mandarin, where (as in Japanese) there is no syllable /si/, but it's not especially difficult for Mandarin speakers to pronounce /si/.) I'd be interested if you knew.
From what I’ve read, it’s been “tsu” at least since the Heian period (so for roughly a millennium), and there is no clear evidence that it has ever been “tu”.
This seems unlikely. The pronunciation was tsu before WWII. But the organization of the syllabary strongly suggests that the pronunciation was once tu.
I don't know to what degree the syllable 'tu' is viewed as impossible in Japanese as opposed to merely nonexistent. (Compare Mandarin, where (as in Japanese) there is no syllable /si/, but it's not especially difficult for Mandarin speakers to pronounce /si/.) I'd be interested if you knew.