- Watashi, Watakushi and Atashi
- Ore, Oira and Ora
- Own Name
- Washi and Asshi
- Ware and Uchi
- Jibun and Onore
- Plural, We
- Possessive, My
- In anime names
- keeki wo tabemashita ケーキを食べました
[I] ate the cake.
This is, of course, unless there's something in the context of the conversation that indicates otherwise.
- kare ga nani wo shita? 彼が何をした？
What did he do?
- keeki wo tabemashita ケーキを食べました
[He] ate the cake.
The words below, "first person pronouns", or ichinin-shou 一人称, all perform the same grammatically. They're all nouns, pronouns, which you use to talk about yourself.
You can replace watashi with boku, or ore, etc. without changing the meaning of the phrase. However, each word has a special nuance attached to it. So it could add a hidden meaning. You can tell someone's a woman, a man, or perhaps a butler depending on the first person pronoun used.
The word watashi 私 is the most basic way to say "I" in Japanese. Anyone can use it, male, female, young and old, and it doesn't carry a lot of nuance with it.
If you had to pick a word, this one would be your best bet. The kanji of watashi, 私, also shows up in words related to "private" and "personal", which just shows how closely related it is to that meaning.
- shiritsu 私立
Private establishment. (like a private school)
- shiyou 私用
The word watakushi 私, which, as you can see, has the same kanji and sounds like watashi, also means "I" but it's used as a more formal version of watashi.
So watashi would be your casual "I" while watakushi would be your business "I". However, recently, there have been reports of teenagers using that word more casually, so who knows if its nuance is going to stay the same in the future.
Just like watakushi, atashi is derivated from watashi, but it has a certain peculiarity: the word is used exclusively by females, girls and women, though not all of them, only some of them.
Japanese is a gendered language. There are many words that are used specifically by women that aren't used by men and vice-versa. Atashi is one of them.
The word boku 僕 is used almost exclusively by boys, children, and it carries with itself a childish nuance.
Basically, boys learn to call themselves boku first and then, when they become adults, use watashi in their workplace and society in general. However, using boku to say "I" all the time means you get used to that word. Stopping using boku and starting using watashi takes some effort, so there are some men who still use boku even after becoming adults.
The word ore 俺 is also a male word, however, unlike boku, it doesn't carry a childish nuance but an assertive nuance. An air of superiority.
Because of this, using ore 俺 is kind of rude and shouldn't be said at all at workplace, with strangers, etc. Children, friends, romantic partners, family, those won't mind, but other people will mind.
In some anime, there are characters who call themselves ore-sama 俺様, which is like trying to call yourself far superior to others. This is because, on top of the nuance in ore, the sama 様 honorific is only used for people whom you consider superior to you.
Once again, the best word to use to communicate with strangers in real life just the plain old watashi.
Oira おいら and Ora おら
The words oira おいら and ora おら are just like ore, used mostly by males, but they aren't as commonly used. They're just another way of speaking.
A way to to say "I" in Japanese that is used by children is to use your own name instead of a pronoun. Though it's common for young children to do this, it's frowned upon in not-so-young children.
Since most anime features characters 10 years old and above, you'll rarely see this way of speaking used.
- fuuka ga yotsuba kaitekureta! ふーかがよつばかいてくれた！
Fuuka drew me! (said by Yotsuba)
- yotsuba mo yaru! よつばもやる！
I'll do it too! (said by Yotsuba)
Washi わし and Asshi あっし
The word washi in Japanese is used mostly by older males, and asshi is just a variation of it. Neither are common. They just lie on the other side of the spectrum compared to boku, which is used mostly by children.
Ware われ and Uchi うち
The words ware and uchi are two words which are rarely used as a first person pronoun. The word ware can also mean "we" sometimes.
- watashi no kuni dewa... 私の国では...
In my country...
- ware no kuni... 我の国...
In our country...
And the word uchi can also be used to talk about your home or family instead of yourself.
- uchi no musuko うちの息子
- uchi ni terebi wa nai うちにテレビはない
There's no TV home.
Jibun 自分 and Onore 己
Another two words which I think are interesting to talk about are jibun and onore. In Japanese, they don't exactly mean "I" but "oneself," so, besides being used to talk about yourself you can use to talk about other people other selves.
- jibun ga nanimo dekinai kuseni 自分が何も出来ないくせに
Even though I can't do anything myself.
Even though you can't do anything yourself.
- onore no chikara wo shiri 己の力を知り
To know your own power.
Another way to think about these is just as "self" and not "yourself" or "myself." Who exactly you're talking about is usually hidden in the context of the conversation.
To say "we" in Japanese you can use the two pluralizing suffixes used to pluralize people. These are tachi 達 and ra 等.
- watashi-tachi 私達
- ore-tachi 俺達
- boku-tachi 僕達
- kimi-tachi 君達
- kare-tachi 彼達
- jibun-tachi 自分たち
Though they mean the same thing, the ra suffix shows up in some words tachi does not and vice-versa.
- boku-ra 僕等
- ore-ra 俺等
- kare-ra 彼等
- aitsu-ra あいつら
Neither pluralizing suffix is used for things. Only for people or things treated like people, like pets for example. In Japanese, the same word often works in both singular and plural. For example, hon wo yomu 本を読む could mean either "read the book" or "read the books."
Another way, for ware 我, it has its own plural which is wareware 我々.
- ware no teki de aru 我の敵である
[It] is my enemy.
- wareware no teki de aru 我々の敵である
[It] is our enemy.
There are other words which have plural variants like this. The word hitobito 人々, for example, means "the people," while just hito 人 means "person" or "people." The difference is that hitobito always talks about multiple people.
Since we are here anyway, the way to say something is mine is Japanese is using the grammatical particle no の. It works with any word which means "I."
- watashi no ie desu 私の家です
It is my house.
- boku no inu da 僕の犬だ
It is my dog.
- ore no gakkou da 俺の学校だ
It is my school
- watashi-tachi no yume 私達の夢
- jibun no kibou 自分の希望
It works with any other words, but then the owner of the thing won't be "I."
- kare no ie desu 彼の家です
Names of Animes
- watashi ga motenai no wa dou kangaetemo omaera ga warui 私がモテないのはどう考えてもお前らが悪い!
No matter how you think about it, it's you guys fault I'm not popular.
- jitsu wa watashi wa 実は私は
The truth is I... (something)
- maji de watashi ni koi shinasai! 真剣で私に恋しなさい！
Love me for real!
- watashi ga motete dou sunda 私がモテてどうすんだ
What am I gonna do if I am popular
- boku dake ga inai machi 僕だけがいない街
The city only I am missing.
- boku no hiiroo akademia 僕のヒーローアカデミア
My hero academia
- bokurano ぼくらの
- boku wa tomodachi ga sukunai 僕は友達が少ない
I have few friends
- ore monogatari!! 俺物語!!
I story. My story. The story of "I". (something like that)
- ore no imouto ga konna ni kawaii wake ga nai 俺の妹がこんなに可愛いわけがない
My little sister can't be this cute.
- yahari ore no seishun rabukome wa machigatteiru やはり俺の青春ラブコメはまちがっている
As I thought, my teenager love comedy is wrong.
- ore, twintail ni narimasu 俺、ツインテールになります。
I'll become twintail.
- kyou kara ore wa!! 今日から俺は！！
From today on I...