I saw this one at one time or another, manga/clamp style anime. Kamui returns to Tokyo to protect his two childhood friends, Fuma and Kotori. He then learns of two opposing forces, the dragon of heaven who want to save humanity and the dragon of earth who want to destroy mankind. Kamui has to choose which one to protect.. and of course he sides with protecting humanity and his friends. The dragon of heaven consist of 7 members that are 7 shields that protect the earth and mankind, and the dragon of earth must destroy each one of them in order to succeed in destroying mankind. Kamui doesn't think he is strong enough, or could even stand up to that kind of power, but his friends are counting on him and so is all of humanity, so he has no other choice! Don't remember the end to this one either =O im sure it was good ^^;