There are 20 characters with 16 lessons each. Every character should take about 10 minutes each to finish.
Character Challenge Tips: Time your moves perfectly; it's not all about how fast you string your moves together, but more relative to how well you time them. Try to aim for a "fast" move selection. (An on-screen text will pop up.) Another thing to keep in mind is if you're too far away to hit your opponent, then you may have to kick in order to move in closer to be able to attack them. In certain sections of challenges, you will be required to avoid attacks; in order to do this, you have to dodge them by leaning to the side. Make sure you dodge their attacks at the EXACT moment they strike you or else it may not count.