If you're looking for manga similar to Kamikaze Kaitou Jeanne, you might like these titles. All recommendations are made by Anime-Planet users like you!
Daisuke Niwa is an ordinary teenager who has a crush on his fellow classmate Risa Harada. But when Risa turns him down after he declares his love for her, Daisuke discovers the secret of the Niwa family: on their fourteenth birthday, Niwa males transform into the legendary Phantom Thief, Dark! Dark is set on stealing art and making mischief, but things become complicated when he falls for Risa's twin, Riku. As if that isn't bad enough, one of Daisuke's classmates, Satoshi Hiwatari, seems determined to capture Dark! Can Daisuke win Risa's heart, while hiding the secret of Dark and evading the police?
KKJ is the same concept as D.N.Angel, with the idea of phantom/alter-ego thievery whilst keeping a secret romance - however, in KKJ, the main character's gal-pal is attempting to capture her thief alter-ego, and her love interest is also a rival thief, rather than the detective and the rival thief being one person in D.N.Angel.
These two mangas/animes are a lot like eachother, with the ideas of people who turn into phantom theives (Daisuke Nia and Kusakabe Maron) with best friends who are trying to catch their alternate personalities. (Hiwatari Satoshi and Toudaiji Miyako.) The protagonists also both have good friends (or love interests, in KKJ's case, and if you ship Satoshi and Daisuke :P) who are secretly there enemies, though they do catch on. In short, though they are similar they are both very original, fun, and worth a try.
Haine Otomiya is a student at the elite Imperial Academy. A one-time gang member who was put up for adoption by her father, her life changed when she met Shizumasa Togu, president of the student council and ‘emperor' of Imperial Academy. Haine quits her gang and enrolls at the prestigious private school in the hope of winning Shizumasa's love. When she is hired as his school bodyguard, she's thrilled; but can she survive the drama of the student council? As secrets spill and relationships form, Haine is pulled further into the world of the elite and powerful, where wealth is everything and social status is the basis of all relationships. What's a girl to do?