User blog comment:ConfettiYeti/Wait, Hetalia Was Flagged As Innapropropriate On YouTube?/@comment-25925099-20150203003158

It's rated TV-MA because of profanity, crude humour and adult situations - that's what FUNimation says. Personally, I find it ridiculous, but I doubt that we could change their minds. Maybe it was flagged because others maybe got offended by things in it?