Bad Japanese Words Your Teacher Won’t Tell You 

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Warning: This post contains language not appropriate for young readers. 

Curious about curse words in Japanese? We swear we won’t tell! (no pun intended…)  

It’s easy to get the impression when first learning Japanese that everything is ultra-polite and it’s impossible to sound offensive. 

But just like any other language, Japanese comes with its fair share of profanity. 

Bad words are called warui kotoba (悪い言葉) and cover a wide range of vocabulary including swear words. 

Speaking of swear words, cursing in Japanese ranges from showing enthusiasm to explicitly offending someone. 

Like any curse word, they sound aggressive and are not used often unless you’re with friends, wanting to start a fight, or… you’re someone that swears a lot!

These words are not suitable for most conversations but at least if someone is messing with you, you’ll be able to understand what’s going on and if need be, respond! 

Without further ado, here are the bad Japanese words your teacher won’t tell you! 

Disclaimer: We do not advocate the use of these words under any circumstances. 

Kuso: the closest thing to the ‘F word’ in Japanese, but not the F word

If you’re wondering what ‘the F word’ is in Japanese, there is no direct translation but kuso is as close as you’re going to get. 
In this section, we reveal just how versatile this bad Japanese word is!




Kuso is less harsh than the F word in English because the meaning of kuso is actually ‘sh*t’. Its kanji (糞) literally means poop / faeces. 

Kuso is used as an expletive to react in anger, shock, disappointment and frustration. Depending on how you say it and in what context, kuso can be as innocent as saying ‘damn!’ or as vulgar as ‘f*ck’ in English.

If you just lost a game and you’re pissed off, you can say kuso in the same way as saying ‘dammit!’ or ‘sh*t’:

Ahh, kuso!
Ah, damn / sh*t! 

And when you’re losing, almost any game can suck so you can also swear about the game, even if you like it and you’re just mad that you’re not winning: 

This game sucks! (This game is sh*t!)

A young Japanese man playing a video game and saying a swear word

Kuso is also used as an adjective and an intensifier like the word ‘very’ in English. 
When used in this way, its meaning is similar but slightly less intense than ‘f*cking’ in English as in ‘f*cking cool!’.

This usage is more common amongst young males: 

(Tastes food)
Kore wa kuso umaa! 
This is f*cking delicious! (or friken / bloody delicious)

If you want to express such feelings without sounding vulgar, you can use slang words like meccha or chou instead! 

Kuso majime

クソ真面目 / くそまじめ

Goody two-shoes

As mentioned, kuso is used as an intensifier and another common insult is kuso majime. 

You might remember the word majime (serious) from our Japanese slang post because this is where the slang word maji de (seriously?!) comes from. 

If you want to poke fun at someone who takes themselves too seriously and can’t take a joke you can say kuso majime (lit: f*cking serious).

Kuso kurae


Eat shi*t

Our next bad word featuring kuso is created by adding the word kurae next to it to tell someone to ‘eat sh*t’. 

Kurae is the imperative form of the verb kuraeru, which also means ‘to eat’. 

If you don’t watch anime often, you might not be familiar with the word kurae. You may be wondering why kurae is used instead of the verb for ‘eat’, taberu / 食べる, as in kuso tabe!(クソ食べ!)

Notice the kanji for kurae is very similar to the one for tabe

  • 食べ:tabe
  • 喰らえ:kurae

But if you look closely, kurae has the kanji radical for mouth (kuchi / 口) to the left of it. 
Aside from meaning ‘to eat’, kuraeru emphasises the act of being on the receiving end of something bad and when used in its imperative form, kurae, it means to ‘take damage/trouble’, ‘to take a hit/punch/blow’ and in this case ‘take sh*t!’  

Kuso tare

クソ垂れ / クソタレ

Sh*thead / sh*t face

If you want to create some less than pleasant imagery, you can do so with kuso tare, which literally means ‘dangling / hanging poop’ but is the equivalent of ‘sh*thead’ in English. 


下手くそ / へたくそ

Hopeless, useless

Hetakuso is a rude way to say someone is severely incompetent at doing something, similar to ‘hopeless’ or ‘useless’ in English.  

The kanji characters that make up heta / 下手 mean ‘lacking skill’ and are the opposite of jyouzu /上手 (which you might know means ‘skillful’ or ‘well done’).  

When you add kuso, you get a blunt way of telling someone that they basically suck at whatever they’re doing. 

Anta maji de hetakusou ne.
You’re really bad at this. (You suck at this). 

Studio shot of Japanese businessman wearing suit against white background and pointing angrily at camera shouting bad swear words

Hetakuso should only be used in informal settings with close friends because it contains the word kuso.


畜生 / ちくしょう


Chikushou is used in the same way as kuso to say ‘dammit!’ or ‘sh*t!’ but only as an exclamatory phrase (not as an adjective or intensifier). 

Fuzakerunaa, chikushou!
You’re f**cking kidding me, sh*t!

Ironically, chikushou / 畜生 originates from buddhism and was used to refer to the untamed nature of animals or ‘non-human creatures’. Kind of like saying ‘brute’ or ‘beast’ in English. 

Fuzakeru na


Don’t mess with me / F*ck off

Fuzakeru na or the more colloquial version, fuzakena comes from the verb fuzakeru / 巫山戯る which means to ‘fool around’ but when said with an angry tone of voice, it instantly becomes a threat. 

If someone is bothering you, you can use fuzakeru na to tell them not to mess with you. 

Fuzakeru na is also used to express disbelief, kind of like maji de (seriously?). It’s more abrasive though because the nuance is more like ‘Get the F outta here!’ or ‘You’ve gotta be f***ing kidding me!’. 


意地悪 / いじわる

Malicious, ill-natured, unkind 

Though still not nice, ijiwaru is one of the softer bad words on this list used towards someone who is ill-natured.

When working in Japan I heard ijiwaru used often in a playful way, even by adults, to point out someone who might have intentionally been a little mean. It’s kind of like saying ‘You’re a bully’ or ‘You’ve got a bad heart!’

Ijiwaru da ne, anata wa!
意地悪だね, あなたは!
いじわるだね, あなたは!
You’re evil aren’t you?

Japanese woman with purple hair shouting angrily down a pink telephone


野郎 / やろう


Yarou means ‘b*stard’ and is usually put at the end of a sentence to rudely address someone who you’ve most likely just yelled / sworn at. 

Yarou is often paired with kono (this) as in kono yarou! (this bastard!) to insult someone. Kono yarou can also be translated to ‘this f***er’.

If someone is saying yarou to someone else, they would most likely either be close friends joking or two people in the middle of an altercation. 


馬鹿 / バカ

Idiot, moron, fool

We already featured baka on our Japanese slang word post, but need to mention it again because it can be used with other words on this list to create a more negative nuance than just slang.

Baka ka, kono yarou!
You’re a stupid ****** aren’t you?



Stupid, Idiot (Kansai-ben)

Aho is Osaka’s version of baka and interestingly, it’s not taken offensively when used in Kansai. If you use aho outside of the Kansai region, however, it’s a major insult. 

In contrast, baka is from Tokyo and should not be used in Kansai, even if it’s said in a joking way! This is because baka is a slang word from the Kanto region and people in other parts of Japan are not used to hearing it in this way! 

Shinee (shineh)

死ねえ / しねえ

Die / Go to hell

Shine (pronounced shi-neh) is the imperative form of the verb ‘to die’(shinu / 死ぬ) but the meaning of shine is closer to ‘go to hell’. 

Though it might not sound like a swear word to shout this at someone in English, the nuance of this word is like ‘F you!’ 

Many Japanese speakers agree that when used to verbally attack someone, shine is extremely offensive. 

Rude pronouns

Pronouns can be used in Japanese to provoke someone when things get heated.

Using any second or third person pronoun already sounds abrasive in Japanese but when you use a rude one: double whammy!


奴 / やつ

Thing, guy, face

Yatsu is a slang that has no direct translation in English but when used to offend, it’s a sloppy way of referring to a person in Japanese.

The word yatsu is used to refer to objects in the same way as koto / 事 and mono / 物, making it sound scornful when used for a person. 

The kanji for yatsu, 奴, dates back to the Edo period and originally meant slave, servant or companion. 

Nowadays, yatsu can be used to deliberately address someone in an inferior way. 

The tricky part is that yatsu is a familiar and even affectionate way of saying ‘guy’ as in kono yatsu ‘this guy’ or ano yatsu ‘that guy’ so you will hear it all the time in Japan. 

But when used outside of this context, it means ‘that thing’, ‘that one’ or ‘that face’ with an intense feeling of disrespect. 

Yatsu plays a role in the formation of the two pronouns below, so read on!

Koitsu / Aitsu

こいつ / あいつ

This guy / That guy

Like yatsu, koitsu and aitsu are rude ways of calling somebody out.

Koitsu is the combination of kono + yatsu and when used aggressively, is a derogatory way of saying ‘you’ meaning ‘this thing/one’. 

Aitsu is a blend of ano + yatsu and is a third-person pronoun meaning ‘that guy’ or ‘that thing over there’ to rudely refer to someone distant from the speaker. 

In an escalating fight situation, someone might say:

Koitsu, maji de kuso!
You’re seriously (a piece of) sh*t!

It’s important to note that like yatsu, both koitsu and aitsu are familiar pronouns used regularly in informal conversation in Japan. 

However, that does not make them polite. To better understand how koitsu compares to other words for addressing someone in Japanese, see the image below:  

Finally, a gentle reminder that context is key in Japanese. Always pay attention to non-verbal cues like the tone of voice, eye contact and body language of the speaker when you hear these bad words being spoken! 

For more on rude pronouns, see our article on How to Say You in Japanese.   

Bad Japanese words

How many of these bad Japanese words and expressions did you know? We hope you enjoyed learning them – just remember, we don’t advocate actually using them!

You won’t come across many bad words or slang in your average textbook or language course. If you want to learn real Japanese, as it’s spoken today, we recommend JapanesePod101! It’s an online, audio and video based Japanese course. The content is fun and always up-to-date. There are hundreds of learning pathways to choose from, depending whether you want to learn business Japanese or casual slang.

Francesca Rex-Horoi

Francesca is a freelance copywriter and teacher, who moved to Tokyo from New Zealand at age 24. A linguistics and ESL major, she spent 3 years teaching at an all-boys high school. Now based in France, she remains a self-confessed Japanophile who loves kanji, cooking, cats and the outdoors.

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