@HOOfan_1 that is half correct, men and women can use the term "Watashi" to refer to themselves, or the more formal "Watakushi". Men also have "Boku" as well as "Ore", the first being an informal way of saying "I", and the second a rather bold/rude way of referring to oneself. The term "Atashi" is actually just "watashi" with the "wa" at the beginning replaced with an "a" to give it a more cutesy sound, and it is by no means a specific way made for women, but it is mostly used by women, or rather, young women for the most part. At the same time, a woman can also use "Boku" to refer to herself to give their words a more masculine or bold feeling. You have a more detailed explanation here: http://nihonshock.com/2009/11/the-many-ways-to-say-i/
It still lacks quite a few words, and not all of them are explained very deeply, but it will give you an understanding, albeit superficial, of the different ways to say "I".