Originated in 4chan's /a/ board. A poster was describing his feelings towards the Fate/Stay Night character Archer, and mistyped "gay" as "gar".
"You are gar for badasses, but gay for traps."
Derived from a typo ('gar' instead of 'gay') on 4chan's /a/nime image board when referring to Archer from the H-game and anime series "Fate Stay Night".
"Of course. Everyone's gar for Archer."
Nowadays "GAR" is used to describe characters that have reached the utmost levels of manliness. Said levels being judged looking at:
- The character's build (the more muscles he has the manlier he is).
- The ability to shout his attacks (GETTA BIIIIIIMU!, ROCKETTO PAAANCHI!, ATATATATATATA!!), though this is not necessarily a must.
- And finally the power to bring manly tears for the viewer (through either a speech brimming with awsomeness, a manly death, the end of the series, all of these combined etc.).