An incorrect romanization of the japanese, "Good Morning!". Ohayou is the correct spelling (the u is silent) and is the informal version of Ohayou Gozaimasu.

Ohayo is used among friends and people who are of similar age.

Intelligence agency term for "psychological operation". A government or corporate-sponsored operation, usually taking the form of a "terrorist attack" or "crazed gunman on a spree", with the intent of panicking the public into demanding more police and laws inhibiting freedom. Psyops are usually carried out by drugging a civilian or group of civilians with aggression-promoting drugs, psyching them up, arming them, and sending them out to commit mayhem. Government-sponsored terrorism. See also blackshirts, conspiracy

Japanese for "Hey"
More casual than Konnichiwa which means "Hello"

good morning in japanese, can also be said as ohayo gozaimasu