User blog comment:Wolf night10/The Final Getsuga Tenshou/@comment-1961713-20100610151408

Ohh kendo, tae-kwon-do, judo. Like Ichigo he joined karate-dojo early in his childhood. So he does not need to learn on how to stand when using sword as all Japanese art of self defense do teach you all the same techniques only the execution may differs. Kendo if you were referring in Manga and Anime when Kenpachi defeated Nnoitra using kendo, he briefly explained it the techniques were taught by the Captain Commander to him, and most Japanese warriors should have this knowledge. Yes this is more than an art of self defense or on how to attack using a sword, using 1 hand or 2 hands.

But for Getsuga Tenshou it should be more on how to increase Ichigo's reiatsu current level of attack, but strictly I believe Getsuga Tenshou could only be learn by wielders of Zangetsu, most probably Isshin and of course Ichigo, but until then we are not so sure about this and inconclusive.