Taking over random Anime Opening Posting until I get bored, forget or the original poster resumes [Day 16: The World God Only Knows]

12 Episode anime from 2010 with two more seasons, based on a manga by Wakaki Tamiki. It's one of those stories that's surprisingly good in spite of the questionable concept.

The song is "God only knows Daisanmaku" and it was made for the anime adaptation.