I don't really think Roxas has a full heart, I think it's a little more... well half of a heart at least. And if he doesn't he’s the closest one in the organization to have a heart. He has emotions at the most and I guess feelings, and don't those come from your brain? I remember someone saying (from KH 358/ 2 days game) that higher-class nobodies do have brains. So since Roxas is a special nobody he can maybe feel more emotions and feelings because his real self is still alive. But does that make him have a heart?
