Kama (鎌) are a traditional Japanese farming implement. They are similar to a sickle and used for reaping crops. Taika forbid students to use 'live' kama in training in the dojo. He did once give me a live kama and have me trim the weeds along his privacy fence. That would be the extent of live training. Before becoming an improvised as a weapon, the kama was widely used throughout Asia to cut crops, mostly rice.