She told me a lot of things about them and she just kept saying kawaii so I thought she became otaku. I told her that but she strongly denied.
What is the boundary between fan and otaku?
My answer is when you start to search about it and know something uninterested people do not know is the turning point.
How can she be non-otaku even she made a Twitter account for them?
If she is just fan, who is otaku?
In my opinion, she is definitely otaku.