All Asians Know Martial Arts

In Western-made works, Asian characters, especially those who are otherwise unassuming Funny Foreigners, are likely to know some kind of martial arts and demonstrate it proficiently, if not superlatively. For instance, the stereotypical Japanese character in many Western works written in the first half of the 20th century will probably demonstrate his jujitsu skills on some other character at some point.

See also Everybody Was Kung-Fu Fighting. All Chinese People Know Kung Fu is a similar trope, but is about how Japanese (one Asian group) view Chinese (another Asian group). All Monks Know Kung Fu is this trope applied to all kinds of monks. Can lead to a Chop Sockey.

Anime and Manga
In The Brave of Gold Goldran the students are prisoners in X-stan and the queen challenges their teacher to a competition that includes a martial arts tournament. When she is asked if this is fair, she replies that it is okay since all Japanese people are masters of karate.

Comic Books

 * The current series of Jonah Hex gave his wife Mei Ling kung fu skills despite her never displaying any during the original run of the comics.
 * Y the Last Man - Shortly after the three main characters start traveling together, Yorick mentions that Dr Mann has less to worry about than him. She asks if he thinks her being Asian automatically makes her some kind of martial arts master; he just meant she looked "pretty ripped." "Oh. Thank you. I used to be into pilates."

Film

 * Comes up in the comedy They Call Me Bruce? (not the one with Bruce Campbell). Since he's asian everybody assumes he knows kung fu—and he uses this fact to escape from a would-be mugger.
 * In the beginning of The Tuxedo, Jackie Chan gets his ass walloped by a NY cyclist and notes regretfully that not all Asian people are Bruce Lee. Of course this all changes the moment that he gets the titular magic tuxedo from Jason Isaac.
 * Discussed and Lampshaded in the new Karate Kid movie: after telling his mother that he's being taught kung fu by the maintenance man, Dre replies, "Mom, it's China - everyone knows kung fu."
 * This trope was discussed, lampshaded, and ultimately averted in Revenge of the Nerds; an Asian student was asked by a Jerk Jock if he knew martial arts. When the student confirmed that he didn't, he had a jock-strap pulled over his head.
 * In the second Crocodile Dundee, Mike Dundee is rescued by a Japanese tourist who jump kicks the mooks away. The Japanese man then takes a picture of Mike because he thinks he's Clint Eastwood.

Live Action TV
""I had no idea that there were that many Asian surgeons in this hospital!""
 * In an episode of Lovejoy, a Japanese customer helps Lovejoy escape some thugs by pretending to know martial arts. They believe this trope and run.
 * Played for laughs in Scrubs when one JD's innumerable Imagine Spots turns into Turk and the Todd kung-fu-fighting a mob of other surgeons for the chance to get into the good graces of a senior staff-member.


 * Top Gear once had the Chinese version of the Stig. Unlike British Stig, driving is his second favorite thing to do. His first is to go around and attack everyone around him kung fu-style, including the presenters, camera crew, and track officials.

Music
""Take a close look, I am asian. And this means I know karate!""
 * Lampshaded (of course) by Knorkator's Arschgesicht, which is sung by one of the band members small son who has a thai mother.

Theatre

 * Billy, the "Jap butler" in The Bat, practices jujitsu on Richard Beresford in an attempt to prevent him from entering.

Video Games

 * In Earthbound, Poo is the only Asian party member, and he actually gets a disadvantage to his attacks when he's equipped with weapons apart from his Infinity+1 Sword. However, from what we see of his home country, it's more akin to India than China or Japan.

Web Comics

 * Something Positive mocks this. Peejee punches a guy in the crotch and calls it her 'mystical Chinese dragon punch' or something.
 * Doctor Sun of Girl Genius. Frankly, it wouldn't be true to its pulp roots if he didn't.
 * Mind you, having a strong personality in this setting more or less equates to the ability to kick ass, and Doctor Sun has one of the fiercest wills in play, s he had to be able to kick ass. His granddaughter has shown no sign of sharing this ability; the most martial thing she's done is yell at people over a clipboard.
 * Nanase of El Goonish Shive is a Japanese-American who was introduced as a highly skilled Supernatural Martial Artist. In, y'know, white-boy Elliot's rather absurd dojo. Where she was the only Asian, and the sensei is black and seven feet tall and based his style on anime....

Western Animation

 * Futurama mocks this trope in the episode "Where No Fan Has Gone Before". Asian-American George Takei complains that Kirk should not expect him to know karate just because of his Asian ancestry. It turns out that he does (which is true in Real Life) but that they shouldn't have assumed that he could.

Real Life

 * In China the children are taught Tai Chi in their physical education class (P.E.). In Japan, they do Kendo in their physical education class (P.E.) as well. Additionally, many high schools in Japan have clubs for Kendo (fencing), Kyudo (archery), Naginata (halberd/spear), Karate, and Judo; these clubs are more like sports teams than clubs though.
 * Korea has similar clubs of kempo and tae-kwan-do, among other martial arts. It should also be noted that young men must enlist in the military which means a significant number of citizens have received combat training.