Yeah but with each rank there are more and more jutsus and take in consideration that a Sensei has multiple students + he of course has his personal life, so it might take even more than a month. There are people that do some training for like 6 months. One reply each week, due to limited online time. There is a lack of Senseis but still not anyone can become one because it would just be a mess then. A person must prove worthy to become a Sensei. My suggestion is that you just stick around, getting your post count up and waiting for training opportunities. There's nowhere to rush anyway. You won't have anything if you have a countless number of jutsus but don't know how to use them. If you have and excessive amount of free time I suggest that you go to the Battle Tests section. There you can find very nice battles and that way you can already gather experience and work on some methods and combos for later.