You have to read Kamisama Hajimemashita~ ♥ Other manga that are tagged with shoujo: I really enjoy Dengeki Daisy and Houou Gakuen Misoragumi. And manga that are tagged with josei: Karneval, and Are You Alice?. I absolutely adore both of them.
Kamisama Hajimemashita is wonderful! There's an anime of it to boot and the art style is just too cute. XD For light-hearted and cute shoujo, you can go with Ouran High School Host Club, High School Debut, Kimi ni Todoke, and the hilarious Lovely Complex. I also suggest Black Bird if you want something a bit more mature. The art's pretty good and the story plot is well-delivered.