Hmm, I don't know how to start this, but I was wondering if anyone could help me.

I recently found a fanfic whose plot sounded oh so similar to a manga that is online at Mangahere and Mangafox (yes, I know, I shouldn't be using those sites). Does that count as plagiarism, even though manga scanlations are made by people like us and aren't at all related to the mangaka at all? 

The plot sounded very familiar, and I have a hunch that some of the sentences found in the story are taken from the manga scanlations itself. I'm not sure, and I haven't found time to compare the two. But, right now, I'm keeping an eye on that fanfic. I asked the writer about it, but she/he did say that the storyline was going to be different. How different I cannot say because the chapters that have been posted so far seem like they're from the manga itself.

If anyone could help me on this, that'd be great.

And I could care less if that person found this blog.