An as of yet untested sex act in which the perpetrator, whilst being fellated by the victim, screams "BANZAI!!!!!" and rips a deafening (preferably wet) fart directly in the face of said victim. Extra points are awarded if victim is either drunk from excessive saki or is somehow dressed as a geisha.
"I no longer have a girlfriend after our night in Tokyo ended with a Japanese War Tuba at the hotel."
by Gjers July 10, 2006

When you're having sex with a girl in reverse cow girl position and then she gets up and shits on your dick. Then you cum on your own dick and she sucks it all off.
by Mike Cannon May 22, 2004

Close to the Japanese Rain Goggles but your man only has one nut sack that drops. Picture the Monopoly guy or Mr. Peanut.
I was trying to give my girl the Japanese Rain Goggle but it was cold and only was able to give her a Japanese Rain Monocle instead.
by Mr.Ballsack August 30, 2013

When a man has an extremely large boner and the female/male (depending on preferences) grabs the large boner and bends in a very obstructive fashion, which may lead to a crack in the pelvic area.
I was at my friends and he was having a very pleasurable dream and so i decided to give him the japanese whammy bar.
by 69 Baby Jesus 69 July 1, 2009

When you piss on someones face, getting it all through an onion ring, then shitting all over their face.
by AlimonyBob October 14, 2011

When you eat nothing but chili for a couple of days while holding off the urge to take a shit and when it finally becomes unbearable you stand over your other (preferably in a bathtub) and spray your fountain of explosive diarrhea all over them.
My relationship with my old lady went to the next level when she let me give her a Japanese War Fountain
by Spnanksbdv February 28, 2020

When you insert live squid into your vaginal cavity. Then you squeeze the squid to death inside your vaginal cavity so they become a pile of mush and ink. You lastly push the squished squid out of your vagina into a man’s mouth for consumption, which completes the Japanese Squid Soup.
by Autismo the retardo February 19, 2020
