Guru-Guru Onsen 3 (ぐるぐる温泉3) is a video game for the Sega Dreamcast published in 2002 by Sega and developed by Overworks. It is a collection of games, and the first that includes a hanafuda game, namely Koi-Koi. Non-karuta games featured in the video game are mahjong, reversi, daifugō, and Napoleon. Later in 2002, Dai Guru-Guru Onsen was released for the PlayStation 2, which includes all games from Guru-Guru Onsen 2 and Guru-Guru Onsen 3.
The game is remarkable for having a 4-player game mode for Koi-Koi, where 2 teams of 2 players play against each other.
The Koi-Koi game (just called “hanafuda” in-game) features both a regular 2-player mode and a “2 vs 2” team play mode. All games support both offline play against CPU opponents and online multiplayer, though online play is probably no longer supported since the servers went down.
When playing Koi-Koi, each player or team starts with an amount of points determined before the game (5 to 60 points, 15 by default). At the end of each round, the winning party’s yaku score is subtracted from the losing party’s game points. The first to reach 0 points loses the game. It is possible to set a maximum number of rounds (6, 9 or 12), but by default there is no limit to the number of rounds.
The game uses Koi-Koi rules that are close to the classic Koi-Koi rules that were common in early hanafuda video games.
In the 2 vs 2 game mode, two teams of two players each play against each other. The rules are the same as the regular Koi-Koi game mode, but with the following additions and changes:
The game settings include an option called “show cards” [札見せ, fuda mise], that allows players to show any 2 cards in their hand to their team mate at the start of each round. This option is off by default.