Nippon is a German role-playing game with similarities to the Ultima games of the same time period. After reading a magic scroll, the protagonist Toshiro gets teleported to a feudal Japan with some mild fantasy additions in the form of magic scrolls and monsters. The focus of the game is on exploring the world and solving some puzzles.

Travelling takes place on an overhead world map on which the player character is directly controlled. When the player finds a village, it can be entered which causes the game to switch to a new screen. Here there are various NPCs to find which can be interacted with. Besides the usual merchants where gold is traded for better gear, the player can also try to talk to the peasants. This is only successful if the correct conversational tone is chosen, e.g. subservient or intimidating. Other things to find on the world map are alternative traveling methods, e.g teleports, or paths like fire which can be walked on but hurt the player.

When a fight is started, the game locks the current screen. The player needs to navigate on the screen, go into position to an enemy and pressing a button to start an attack. A victory grants experience points which eventually lead to improved statistics: strength, agility and hit points. The player character needs to eat and sleep.