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1.
japanese. (usually, a woman's) breasts. a tasty treat.
large chested waitress: Would you like any appetizers?
customer: oppai, I'll take two.
by pokute May 01, 2004
 
2.
tits in Japanese, generally used to refer to the larger variety....which are rare in Japan cause most o fthem have small little mosquito bite tits but the ones that have big guns are keepers.
Fuck this sushi shit, I gotta get me some oppai.
by SkinnyPete January 05, 2004