It is hiragana. It is one of the 48 hiragana, just that only 46 are really in modern use.
ゐ "wi" and ゑ "we" just are not really used at all anymore. Also, when you are doing katakana, you will encounter them there too: ヰ "wi", ヱ "we", and also ヴ "vu".
You can still find the katakana "we" in the popular brand of Japanese beer, ヱビス, which is confusingly romanised as "Yebisu" lol.
http://www.sapporobeer.jp/yebisu/May 19, 2015 at 2:04pm