Is gi the karate uniform capitalized?

Answer 1

Generally not unless it's at the beginning of a sentence.

First of all in actual Japanese it would be called keikogi, dogi or karategi not just gi.

Second in actual Japanese there are no such things as capitals.

Third in English usage gi does not fall in to any of the capitalization categories (proper name etc.)

Answer 2

It's spelt like that in Japanese. 'Gi'. However it;s pronounced Gee.

Answer 3

Karate gi is the plural of karate gi. The Japanese language implies plurals by context and does not add an s or other indication to the word.