The Z flag has special meaning in Japan (as well as in naval history generally) due to its connection with and symbolizing of the great Japanese victory at the Battle of Tsushima.
At the Battle of Tsushima on May 27, 1905, Admiral Tōgō raised a Z flag on his flagship, the Mikasa.[3] By prearrangement, this flag flown alone meant "The fate of the Empire rests on the outcome of this battle. Let each man do his utmost". The Battle of Tsushima was one of the most important naval battles of history and this signal is, along with Nelson's signal "England expects that every man will do his duty" at the Battle of Trafalgar, one of the two most famous naval flag signals; the battle is of especial importance in Japanese national mythology.