I was out flying around Skyloft when I discovered the bamboo cutting challenge. At first, the proprietor said I needed to get 15 cuts. I was able to get 17, and got 30 rupees as a reward. He then said I should try and get 20 cuts. He also suggested I get a longer sword, which would help me. (I'm sure that a better sword comes later in the game.)
Do I only get rupees for completing this challenge? Or is there something more meaningful I can earn? What is the maximum number of cuts I'll be asked to make?