Japan has been battling sluggish growth, mounting public debt and a rapidly ageing workforce.
Masato Kanda unleashed an estimated 25 trillion yen to support the currency when it slumped against the dollar.
The central bank has put up its key rate to "around 0.25%" as it tries to ease rising prices.
The account on the platform formerly known as Twitter impersonated Japan's top currency diplomat.
Consumer spending growth slowed as the weak Japanese currency made imports more expensive.
The country's central bank has yet again kept interest rates below zero even as the currency slides.
US currency jumped in value against major world currencies after higher-than-expected inflation data.
Officials are concerned at the yen's slide to its lowest level against the US dollar in 24 years.
The US dollar hit a fresh high on strong employment data and the signal of higher interest rates.
