According to poll at internet provider, Biglobe,  Ippo Tsuko or known as the Accelerator of fantasy sci-fi anime, Toaru Majutsu no Index ranked first in the list anime characters that is a certified lolicon or under suspicion of being one.

lolicon (Noun) (Japanese usage)
derived from the from lolita complex – from Nabokov’s novel “Lolita”.  Someone who is attracted to prepubescent girls [Urban Dictionary]

The Accelerator received 180 out of 968 votes bypassing Bakemonogatari’s Araragi Koyomi (164) and Wagnaria’s Souta Takanashi (123).

Rankings

1. Ippo Tsuko / Accelerator (To Aru Majutsu no Index)
2. Araragi Koyomi (Bakemonogatari)
3. Souta Takanashi (WORKING!!)
4. Hasegawa Subaru (Ro-Kyu-Bu!)
5. Kyubey (Puella Magi Madoka Magica)
6. Kashiwazaki Sena (Boku wa Tomodachi ga Sukunai)
7. Aogami Piasu (To Aru Majutsu no Index)
8. Nagatsuki Sanae (Shinryaku! Ikamusume)
9. Kimura Sensei (Azumanga Daioh)
10. Itaru Hashida (Steins;Gate)

[Source]