Why does the katakana ラ look similar to the hiragana う?


More specifically, is there a historical reason why some katakana characters
look similar to the hiragana ones, as the question suggests?




It is just a coincidence. As you (probably) know, both hiragana and katakana
came into existence as shorthand for kanji. Here's the graph shown on
[Wikipedia](https://en.wikipedia.org/wiki/Kana). So you can see that ラ and う
are derived from different kanji and just so happen to look similar.

[![kana](https://i.stack.imgur.com/NofYJ.png)](https://i.stack.imgur.com/NofYJ.png)




It is just a coincidence. As you (probably) know, both hiragana and katakana
came into existence as shorthand for kanji. Here's the graph shown on
[Wikipedia](https://en.wikipedia.org/wiki/Kana). So you can see that ラ and う
are derived from different kanji and just so happen to look similar.

[![kana](https://i.stack.imgur.com/NofYJ.png)](https://i.stack.imgur.com/NofYJ.png)

