It's about a 14 year old boy named Daisuke Niwa. And the year of is 14th birthday he turs into Phantom theif dark Mousy. And he sends out warnig signals and for Dark to turn into Daisuke he has to steal something. But as soon as you get farther into the series you will see why Daisuke doesn't won't Dark to do anything Daisuke wasn't confident enough to do like (ask Miss Harada out) hint hint.