The plug itself is weird but besides that this would be canon since Smith Hioka did mention that her ponytail is a hair extension and apparently she was trying to cosplay Miku's twintails but could only afford one sidetail.

Looks like the page where he said this is gone (even from the Web Archive) but it was quoted on Reddit: https://www.reddit.com/r/Memeloid/comments/vin3w6/apparently_akita_neru_actually_has_short_hair/

https://akita-neru.at.webry.info/200712/article_14.html

本当はミクのようなツインテールにするため、エクステを2つ揃える予定でしたが、お金が足りなくて断念したのです。

一本だけ、しかも片側にだけ付いているのは、そういう理由があったのでした。

だからホントはショートカットの女の子なんですよ>ネル

In reality, she planned to get two hair extensions to have twintails like Miku, but she didn't have enough money so she gave up on that.

She only got one, and furthermore attached it to the side, that's the reason for that.

So in reality, Neru is a short hair girl