Charapedia recently asked male anime fans the question: Which anime characters are the most pure and innocent? You can view the female results here and the full results for this poll here.
Here are the male results:
10) The Minami Sisters (Minami-ke!)
9) The Doma Siblings (Himouto! Umaru-chan)
8) The Blank Siblings (No Game No Life)
6) The Araragi Siblings (Monogatari)
5) The Kirigaya Siblings (Sword Art Online)
4) The Elric Brothers (Full Metal Alchemist)
3) The Shiba Siblings (Mahouka Koukou no Rettousei)
2) The Kousaka Siblings (OreImo)
1) The Hirasawa Sisters (K-On!)
