Fortunately, Japanese parents are not so deluded as to think children will begin parroting rude language immediately after they hear it. Meanwhile, try to make anyone curse without a censor bleep in an American kids' show, and bam! The censors bear down on your ass like a ton of bricks.

Basically, Japanese doesn’t use “swearing” as we do. Instead, Japanese consists of multiple politeness levels, and depending on your social standing between you and the speaker, your intent, and such stuff, you pick from the appropriate politeness level. You talk up to your teachers for example, while a department head at a company will talk down to his subordinates. There are different levels, and one of the lowest levels to talk to someone is the closest equivalent to our swearing.

A quick example of “eat”. Here are a bunch of different levels of telling someone to eat.

• Omeshiagari kudasaimase
• Omeshiagatte kudasai
• Tabete kudasai
• Tabete kure
• Tabete
• Tabero
• Kue

The proper word to use depends on who’s talking, who’s being spoken to, what their relationship is, what the intent is, and other context things. By going against what’s proper, you can talk rudely, which is what swearing accomplishes in our language (and other similar languages).

Even words like “kuso” have multiple translations, you could call it the “shit” in one case, while in other case it could be as harmless as “dang it!”. You’d even hear “kuso” in Pokemon anime I’m sure, for example. I know I heard it in Beyblade often enough.

Because all of this is so subjective, swearing in translation can vary pretty crazily depending on the translator. Generally, the more experience, the better the swearing turns out. That’s why with fan translations (particularly anime and manga) you tend to see tons of swearing in what would seem to be kids’ shows or what have you.

Also, because of all this, I really doubt the Japanese rating system takes this politeness level stuff into account, since it occurs everywhere in Japanese entertainment. It’s also not taboo. You don’t want to talk in everyday situations the way they do in entertainment, but you’re not going to go to hell or get your mouth soaped if you use the wrong level. You’ll just really tick people off or possibly get killed.