War at Japan Sea is a strategic wargame for Russo-Japanese war. This game issued with Japanese self-published magazine SLGamer Volume 5. Players control either Japanese Navy or Russian Navy. Players manage fleet movement and battle, to control of seas. The basic system of this game is reference from War at Sea (Second Edition). The fall of Port Arthur fortress is a big event in the game. Russian Pacific fleet will be wiped out by fall of the fortress. Russian player can be delay the fall of the fortress by the control of the sea areas. Winner will determine by victory points. Victory points can be earned from control of seas, and also earned from surviving warships at the end of the game.