Anyone who studies Japanese learns early on in her or his study that there are other ways of saying "I" than the standard "watakushi." This is odd from the point of view of the speakers of English and most European languages. Each form of "I" defines the speaker's notion of self-presentation according to gender, station, profession, self-image, and, sometimes, regional origin. This is one peculiar feature of this language and reveals something essential about this culture that pays an inordinate attention to the precise degree of self-condescension in presenting oneself to the interlocutor.
Every language, of course, has hierarchy markers. That they appear in the speaker's designation of her/himself is what makes the phenomenon noteworthy.
I can easily come up with the following twenty odd forms of "I". Some of these are variants of "watakushi" but they are lexically marked and each of them carries a clearly registered connotation.
watakushi: standard form, gender-neutral
atakushi: variant, feminine and affected (ladylike)
watashi: less formal than watakushi, gender-neutral
atashi: further slurred, largely feminine
atai: feminine and lowly (girlish)
washi: masculine, elderly
wasshi: masculine, elderly, coarse
asshi: masculine, coarse
ware: literary, formal
wai: antiquated; also used to mean "you"
ai: a variant of wai
boku: masculine, youthful
ore: masculine, youthful, coarse
onore: literary, formal
oresama: masculine, arrogant
wagahai: masculine, self-aggrandizing
yo: literary, antiquated (not Spanish)
uchi: Kyoto, Osaka and Western Japan
sessha: masculine, samurai, condescending
temae: formal, humbling; could also mean "you" (belittling)
It must be pointed out further that "you" also comes in different words: anata, anta, anatasama, sonata, omae, omeh, temae, temeh, kimi, kiden, kisama, gozen, onushi, etc. They are not as numerous because the preferred form of address is to use the title or name, each with the proper honorific to go with it.
T. Kaori Kitao, 03.03.00