Hangetsu (半月) (Half Moon).
Hangetsu is said to be the oldest karate kata, with the original name being seisan. Master Gichin Funakoshi changed the name from Seisan to Hangetsu and then added the kata into the Shotokan cirriculam. Hangetsu-dachi (half-moon stance) is the essence of this kata, semi circular stepping (half moon) combined with breathing and expansion and contraction. Hangetsu kata consists of 41 movements and the older Okinawan version of this kata is known as Seisan (thirteen).
Neko Ashi Dachi (cat stance) is also used for the first time.
The breathing in Hangetsu should be deep and should be combined with the muscles contraction and expansion. Along with contracting the muscles try and stretch the muscles, rather than pulling everything in.
Try and expand your stomach out when breathing in, then tighten and pull the stomach in when we breathed out, my Sensei used to say this will help use the whole of the lungs, instead of just shallow breathing using the top of the lungs and make your Hara strong.
Hangetsu should be explored in detail and practiced often. This kata also gives the karateka a total mind and body workout. On the slow techniques the muscles tighten over a few seconds, with the body like steel at the completion of the technique, then relax breathe in and start the next technique. My Sensei had a unique breathing rythm for moves 7,8,9 and 10, which we will go into detail in this Hangetsu tutorial.
Hangetsu Kata Tutorial Part 1