female pretending to be male online
Internet slang; from ネット (net) + おなべ (slang for a masculine woman or butch). Used for a woman who presents as male in online spaces. Compare ネカマ (male pretending to be female).
See also: ネカマ
That player might be a female pretending to be male.
They were found out as a female pretending to be male and deleted their account.