Keima Katsuragi's skill at winning women's hearts is so legendary that he's called The God Of Conquests, but that's only in dating video games, not the real world. Suddenly, Keima's life takes a turn for the weird when he answers what he thinks is an online gaming challenge. Instead, he ends up with a demon contract, and now he has to help perky demon hunter Elsie track down a bunch of demons that have escaped from hell! The reason: the demons have hidden themselves within the hearts of a group of random girls, and the only way to get them out is if Keima can make the girls fall in love with him. Also, just to make sure that Keima is properly incentivized, his failure will result in the loss of something important: his head! Hopefully, the tricks Keima's mastered with virtual girls will work just as well with live ones. Otherwise, things are going to get really messy in the spectacular ultimate collection of THE WORLD GOD ONLY KNOWS!