Here in this post, I will explain what “Nari-Ota” (成りオタ）means. “成り” is an abbreviation of “成りすまし” or spoofing, and “オタ” is an abbreviation of “オタク（Otaku)” or geek. That means, Nari-ota are people who pretend to be somebody’s fans, but actually they are not.
In the context of figure skating fandom in Japan, this is a technique to often ensnare Yuzu-fans. For instance, someone who claims himself/herself to be a Hanyu-fan behaves very poorly on Twitter. Sometimes they are real fans who are not considerate enough, but often they are Yuzu-haters trying to undermine the image of Yuzuru-fans or even Yuzuru Hanyu himself.
According to one of my followers, this is a technique often used in the entertainment industry.
(First written on 2020-09-22)
Appropriate English expression will be “decoy fan” or “decoy ‘fanyu'” specifically.
(Edited on 2021-04-30)