To say/pretend you are someone of stature somewhere else, meaningless and not verifiable where you currently are.

One who has a mania for music.

Something a man with a small penis says.

Considering the stereotype of Asian males having smaller penises, this is a way for an average sized American male to make his own penis seem large.

Also the name of a late 1970s punk band. "Big in Japan" is also referenced in the lyrics of several other bands such as Tom Waits and New Radicals, where the phrase is used to describe the singer's supposed fame in Japan, not the punk band.

Big in Japan is an instrumental, experimental band based out of Baltimore, MD. The members of the band make up 3/5ths of Lake Trout. Drums - Mike Lowry, Bass - James Griffith, Keyboard/Rhodes/Soprano Sax/Flute/Drum Machine - Matthew Pierce.

A Japanese woman or women with big breasts.