Bishoujo Battle Hanafuda Koi-Koi is a casual game from Zoo Corporation that adapts the Japanese flower card game Koi-Koi. The game includes a tutorial to teach beginners the rules, where players form scoring combinations called Yaku by matching cards. Players can choose to "koi koi" to continue a round and increase their score, but risk losing points if an opponent forms a Yaku first.The game incorporates Bishoujo characters from the "Rick G Earth" mobile game. Players compete against these characters in a single-player mode across Japan, aiming to collect character cards and achievements. Bishoujo Battle Hanafuda Koi-Koi also provides online multiplayer for competition against players globally.
