I read this manga a few days ago, and found it to be good… Not your average romance manga, but still follows the same unoriginal idea where a demon changes the loner's life... nevertheless, it's done well and is entertaining, touching and funny.
The story revolves around Katsuragi Keima, known on the internet as the "God of Conquest", who is a seventeen year old Otaku that is obsessed with Dating Sims and has no interest in the "real" world, or in the girls that are in it. He is approached by the Demon Elsie, who must work with her new partner(when they chose him they thought he had experience with girls due to his nickname) and together they must fill the gap in girl's hearts, where evil demons reside. To fill the gaps, Keima must make the girls targeted by demons fall in love with him and the demons are expelled after they kiss. If he fails, both Elsie's head and Keima's head explode. The "God of Conquest" must now try to Conquest the real world...will he fail, will he succeed? You'll never know if you don't read!
So yeah, it sounds generic, but it's actually a fun read for guys and girls alike. It may have romance elements, but it's shonen. And who doen't like an Otaku Kira type character?