Ask Lemmy

I am not a native or regular speaker, so take my observations with a grain of salt. In this comment I will refer to people as "males" and "females" in order to not imply some characteristics of gender or a certain age.
There's probably 6 common first-person pronouns (I forgot about one): 私 (watashi), あたし (atashi), うち (uchi), 俺 (ore), 僕 (boku), and 自分 (jibun).

私 (watashi) is the most common and basic pronoun. This is the one that I meant when I mentioned a "mildly formal basic pronoun that doesn’t really reveal much about yourself." In formal speech, it's basically totally flavorless and generic; anybody can use it. In more casual speech, it's a little more feminine. Males are more likely to use 僕 (boku) or 俺 (ore) casually. This is my pronoun of choice when I speak Japanese.

あたし (atashi), sometimes also written as 私, is an alternate abbreviated form of 私 (watashi). I'm not very familiar with this one and I don't think I know anybody who uses it, but I've heard that it's more feminine and more casual than 私 (watashi). Males will rarely ever use あたし (atashi). I have also heard that it has a slight rebellious flavor to it.

うち (uchi) is where we start getting into the interesting ones. In a literal sense, うち (uchi) means house/family. This kind of synecdoche is not uncommon in Japanese, where you can refer to somebody by their house. This is actually where the word "otaku" comes from. In contemporary Japanese, otaku basically means "nerd" but it's originally a second-person pronoun that means "your house," and it was a common formal way for nerds to formally refer to each other. I don't really know much about うち (uchi) usage but it's definitely more feminine. Not quite sure about the level of formality. I quite like this pronoun and I would probably use it if it was a little more neutral.

俺 (ore) is very casual, very masculine, and I've even heard people call it a little bit aggressive or rude if it's used in the wrong circumstance. This is probably the most common male pronoun in casual settings, though it is not really used in younger speakers. This would be a pretty subversive pronoun to use as a female, but I do know at least one female speaker who uses 俺 (ore) as their primary first-person pronoun.

僕 (boku) is maybe the most interesting one. It's masculine, but can be quite polite. It's very common among young boys and my male Japanese friend told me he doesn't use it because it sounds childish (幼い). Despite that, it is still used in older male speakers in a professional setting. It's also worth mentioning that there's a falling-pitch 僕 (boku) which is more childish and a rising pitch 僕 (boku) which is more professional. Rising pitch 僕 (boku) personally gives me the vibe of a professor or researcher and it sounds a little more individual than 私 (watashi), though that's just my impression. 僕 (boku) is also commonly used in songs by female singers. Female usage of 僕 (boku) outside of music is, I've heard, very rare. But in fictional media there's definitely a trope that exists of the "boku girl" and it's really cool to hear. Off the top of my head, there's a vtuber Amane Kanata who speaks with 僕 (boku). My favorite fictional "boku girl" is Tsukimiya Ayu from Kanon. Hearing 僕 (boku) from a character who is otherwise not masculine gives off a really complicated vibe. It's a little naive, bold, boyish, cute, childish, etc. But you should probably not expect to hear it in real life.

自分 (jibun) means "oneself" and is not necessarily a first-person pronoun. You can easily use 自分 (jibun) to refer to "yourself" or "themself" etc. As a first-person pronoun, I think it can be very gender neutral. It also has the quality of slightly distancing yourself from what you say, or trying to imply that you are not imposing yourself on other people. In English, it would be like saying "well, personally" at the beginning of every sentence and "but that's just me" at the end. I do like 自分 (jibun) and it has its use cases. I would say I more often use it as a second- or third-person pronoun though.

Again, my knowledge of these pronouns is pretty superficial as a non-native non-regular speaker but even if I have some details wrong, the proof of concept is still there. Sometimes I wish that the English pronoun system was more robust and I hope for a distant future in which we abandon our silly he/she pronouns that imply nothing but gender and move towards using a variety of interesting second- and third-person pronouns like girlypop and anon.