What is this martial arts movie called?

Ok, you might think this sounds a bit stupid :P but I watched this movie a long time ago and can’t seem to remember the title. I’ll describe the plot so if anyone recognizes it please answer below… =P PLOT-read at your own risk xD (bad grammar alert) =P It begins in ancient times in front of a temple. A teacher is telling hes student he’s going to retire and pass the secret on to him. Some sentences that have to be pronounced to give you a special power. The keeper of the secret lives for a looong time. I think he was for 500 years, until he finds a student to pass on the duty of a guardian to. The student must fulfill 3 conditions. (Don’t remember which ones, I think one of them was to save a princess- which turned out to be a mafia princess in our time, later in the story) The new guardian is still alive in 21 st and is losing hope to find an appropriate student. Some people are familiar with hes secret and they are offering their sons to be trained. But none of them is good enough. One day he meets a young guy who is obsessed with martial arts movies and he managed to learn them just by watching and imitating… That’s when I fell asleep. T.T It was 2 am. xD Hope this wasn’t too annoying. If you bring yourself to read this PLEASE tell me anything you know. I wanna see the entire movie! :(