Where do the Tandoku Renshu, Ni Ju Ni and San Ju Ichi, come from? I've heard them often referred to as kata by most Aikidoka, which according to D. Lowry they are not. Are they exclusive to Aikido or do they hail from older sources? I don't know if this has been asked before, but I was unable to find an answer on any older thread. If I missed one let me know.
Thanks,