For reference, here's an actual top 25 anime characters from polls in Japan. Guaranteed it's nothing like what you'd get from asking that in America.
http://www.japan-talk.com/jt/new/25-most-popular-japanese-cartoon-characters
Kind of vague on where exactly they got the list, though.
Here's IGN's version for comparison:
http://au.ign.com/articles/2009/10/21/top-25-anime-characters-of-all-time
For example, IGN has Rei Ayanami and Sailor Moon in the top 10, whereas these didn't even blip a mention in the Japanese poll. So much for the Japanese obsessing over the submissive kawaii girls more than Americans do.
That's just IGN's wild guessing based on a lot of vague criteria, though. They list Son Goku as #1, with the stated justification that he beat up King Kai who is basically God. That's... an argument you could make, I suppose, but it doesn't tell us very much about anything except IGN, and even there the exact meaning is unclear.
That's...
Dang, now I want to know what the most popular Western animations are in Japan.
Hm, likewise. Do they routinely brings things over at all, though?
Watching Akame ga Kill episode 3. Not even 10 minutes in and we have the standard anime fanservicey trope of "MC walks in on girls changing". Really ruins the immersion, the whole scene feels blatantly shoehorned in. Japan must have a problem with locking their doors or something. It's too absurd and too common of a trope to not have some basis in reality.
I've heard anime has an odd tendency to sex it up beyond what the manga includes, and I think this is an example of that. As for that particular device, I'd guess it's just the least absurd way to routinely show off naked girls and embarrassment comedy without needing any meaningful circumstances or lasting implications.