Accidental Hug

Yusuke: Why don't you quit hugging me, you weirdo?!

Kuwabara: You're the one hugging; I was trying to squeeze you to death!

—Yu Yu Hakusho

A gag where two characters spontaneously hug in a moment of shared joy or affection—and then one or both of them quickly, awkwardly pull away. Maybe they want to maintain their stoic, manly, or jerkish facades. Maybe they've remembered that they're Just Friends, or not even friends. In addition to humor, the device can be used for a Ship Tease, or to show that two characters really do like each other.

Can be a Not So Stoic moment.

A common result of the Man Hug. Compare Security Cling. If somebody's really enthusiastic, you might end up with an Accidental Kiss instead. Can turn into a Gay Moment.

Examples of Accidental Hug include:

Anime and Manga

As seen in the page quote, in episode nine of Yu Yu Hakusho, Yusuke and Kuwabara do this after finding out that Yusuke passed Genkai's third test.

Film - Animated

Happens a couple of times between Kuzco and Pacha in The Emperor's New Groove.
After Jim saves the ship from being destroyed near the end of Treasure Planet, Amelia and Doppler spontaneously hug. The movie uses it for an Aw, Look -- They Really Do Love Each Other moment.

Film - Live Action

In Bill and Teds Excellent Adventure, Bill and Ted hug in relief after Ted's apparent death, and then pull away, both exclaiming, "Fag!"
Jay and Silent Bob in Jay and Silent Bob Strike Back.
Danny and Kenickie share one before the big race in Grease.
Done as a gag in the climax of Major League, where a regular Tribe fan and a punk Tribe fan excitedly hug, then they pull back, then they go back to hugging excitedly
This comes up repeatedly in the Road To pictures with Hope and Crosby.

Live Action TV

Regularly between Chandler and Joey on Friends
In the episode "Sports Medicine", the distressed wife of the Patient of the Week bursts into tears and latches onto House. Given the circumstances he can't really throw her off, and we are treated to a lovely/hilarious shot of House in the middle of a crowded corridor, being clung to and looking extremely embarrassed about the whole thing. Eventually he manages to give her a little pat on the back.
In the Dexter episode "Dex, Lies & Videotape", Deb impulsively hugs Lundy after he clears up a misunderstanding. He hugs her back. Then a crackling police radio reminds them that not only are they (at that point) platonic co-workers, they're in the middle of a crime scene.

Literature

In the 5th Artemis Fowl book, Butler, after not seeing him for three years due to time travel adventures, spontaneously hugs Artemis and just as quickly pulls away, embarrassed at his lack of professionalism. A one-sided example, as Artemis doesn't seem to find it awkward.

Newspaper Comics

Zits
- Lampshaded in one strip: just as Jeremy and Hector are about to hug, they look at each other and then sit down. Hector mentions hugging between males always looks easier on TV, to which Jeremy responds "Let Us Never Speak of This Again".
- In another strip Jeremy and Walt express their mutual affection with an "air-hug" (ie making hugging motions about three feet from one another). That either of them went that far apparently had something to do with it being Walt's birthday.

Western Animation

Danny Phantom.
- In "One of a Kind", Danny and Tucker fall asleep and end up snuggled together. They wake up that way, scream, and yank their arms back.
- With Danny and Sam in "Fanning the Flames". Unlike the first example, this was used for Ship Tease.
Clay and Coach Stopframe in Moral Orel.
In an episode of KaBlam! Henry and June both hug each other, though then Henry found it awkward and pulled away, mentioning, "Let's not get gross here." (meaning kissing). June on the other hand, LOVED the hugging.
Mordecai and Rigby barely avoid this at the beginning of "Temp Check" ("Ah, sick!") Later becomes a Chekhov's Gun to separate Doug from Rigby.