These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Evil Is Sexy: Gaito, The Dark Lovers, Black Beauty Sisters, Sara, Michel and the Winged Ones.
Germans Love David Hasselhoff: This show has a surprising number of fans in the West, which begs the question why no TV station wants to air the show.
Harsher in Hindsight: One thing no one wanted to talk about when the series aired. The entire plot — both the villains' plan and the Lucia/Kaito love story — starts because of a tsunami in the Indian Ocean, which killed Kaito's parents and destroyed the orange mermaid country. A certain real-life tsunami in the Indian Ocean with a similarly high death toll happened the day the anime ended.
Probably justified (and probably invoked) because he's also a crossdresser.
What Do You Mean, It's for Kids?: The more suggestive and bloody manga is rated "13+" in North America, where the Animation Age Ghetto compels manga publishers to put ratings on their books, yet it was originally published in Nakayoshi, a magazine for little girls.
Woolseyism: The Italian dub. The voice acting is great, the songs are possibly, even better than the Japanese ones. They completely substituted J-pop music, to much more pop-rock, and rewritten the lyrics to match the new song. Checkitoutyourselves.
Some countries made Noel's color Indigo, as Aiiro (Deep-Blue), would be hard to translate, and make her too similar to Hanon. Technically, Hanon is aquamarine/turquoise, and not blue, but this often had to be changed too.