a popular trickery game played by Japanese youth in the mid 1990s that involves one participant sticking his thumb up another unsuspecting friend's ass. If the penetration is successful, the participation is required to jump up and scream "Bonga Bonga!" The contest may last the duration of a friendship.
Suzuki: Hey, that's one fine looking dame over by the fire hydrant.
Eugene: Where I don't see a...OW!!!
Suzuki: Bonga Bonga!!!