I'm looking at this picture of the 日米和親条約 (Kanagawa convention) from the late Edo period and it seems rather strange: It looks like the non-kanji parts are rather haphazardly written in katakana ...
Nowadays, katakana tends to be used for gairaigo and onomatopoeia, while hiragana tends to be used for native Japanese words. This is a slight simplification - more information is available here. ...
According to When is the katakana form of wo (ヲ) used?-ヲ-used, を is almost always used only for the particle, and is usually pronounced o (お). There are some dialects where を is pronounced with a ...
How did it come about historically that っ preceding a sound would geminate it? Is it really a little つ or are they just near homomorphs?
In the last century, the ゐ and ゑ characters were eliminated from common use. But it seems like there used to also be a "wu" character that has since been lost. Given that it's a lot harder to find ...
The particle は is pronounced similarly to わ (unlike the rest of the ハ行 kana) when used as a particle; why is this? What historical shifts went on to cause this irregularity?
The ヶ in e.g. 一ヶ月 is a bit of an odd character - it looks a lot like a small version of the katakana ケ, but is it derived from that katakana originally? Or is it a normal kanji? Or is it something ...
Sometime in the early 20th century, usage of the now-historical kana ゐ and ゑ (and their katakana equivalents) dropped off, being replaced with い and え in modern Japanese. What exactly happened here ...