Japanese Plural

This is a small point. There is no plural in Japanese.

Most nouns in Japanese have no plural form, (we have the same in English with Sheep, Shrimp, Deer... although not always true in the South) so you use the same word whether you're using a singular noun or a plural noun. There are rare exceptions when a Japanese noun does have a plural form, but it is not marked by adding an"s" at the end of the word. (Usually the plural form simply repeats the word using the "voiced" sound for the first consonant. Ex: hito - person - becomes hitobito - people - and kami - god - would be kamigami - gods. 

So you would say one waza, two waza. You would not say two wazas. You don't add the English letter "s" to Japanese words to make them plural.

 Two Sensei - Toyama and Culbreth

 

Thus, I would say that I have two sensei, not two senseis. I would study five kata, not five katas. I would visit two dojo, not two dojos. I would also refer to the two Rohai kata rather than the two Rohai katas.