Although this isn't Vocaloid related, it's something interesting I wanted to share that intrigued me for a while and somewhat of a overlooked comparison of Power Rangers/Super Sentai and Madoka Magica. Now before you start, I am aware many Magical girl shows have shown similarities before, but since Madoka is the more notable hit concerning the genre I just wanted to analyze so. This will mainly concern The Might Morphing Power Ranger's (aka Zyuranger) plus some other Super Sentais.
1. The colours of the original 5 (or later 6) team:
Homura-Zack (Though some could argument her as purple, she has plenty of black in her hair and clothing): Black
While Kyubey isn't a magical girl, he could be considered part of their team so he would represent White, reflecting the same colour's of Rangers Season 2's Tommy of the White Ranger (Thus it represents R B P Y B and W)
2. Atleast one member turns evil/becomes corrupt in someform or another. Notably Tommy the Green Ranger (While others have been manipulated before) and Sayaka.
3. The above member uses swords as their main weapon. Sayaka with her blade and Tommy with the Sword of Darkness and to a lesser extent the Dragon Dagger.
4. They both fight witches to an extent: Madoka fights them as their main type of enemy, while The Power Rangers fight Rita who is also a witch (Even her sentai counterpart Witch Bandoora more or so confirms her as a witch)
5. While their weapons vary, the most obvious similarity is that both pink (Madoka and Kimbely) both use bows and arrows. Another similarity is that both Black (Zack and Homura) uses a shield (Though in Zack's case its the Masterdon shield for their Megazord).
6. And the most coincidental or perhaps most symbolic similarity is between Mami and the Yellow ranger/sentai. As you all know, Mami was the first to die in the series, who represented Yellow. Years before, Trini's actress Thu Trang who played the Yellow Ranger died in a car accident in 2001. But if we go back even further, The 8th Super Sentai Series Bioman introduced the first Yellow female sentai (Ranger): Mika Koizumi. While her actress is alive: her character dies in series. But we don't stop there: The very first Super Sentai series Goranger's first Yellow sentai Daita Oowia's portrayer Baku Hatakeyama committed suicide due to his role and other problems he had. Makes it more interesting that the first actor/actresses to die in real life in the main core team both represented yellow just like Mami.
Now I know this analysis isn't perfect, but its just something I wanted to share anyway. Any other notable similarities you find between the franchises? Please share them!:'D
References on the actual series:powerrangers.wikia.com
Power Rangers wikiwiki.puella-magi.net/Main_Page