We have created a new card game, Gakmoro, where two players each have seven cards numbered from 1 to 7. In each round, they secretly choose one to three cards to compete based on their total value; the first player to win two rounds wins the game. The unique feature of Gakmoro is that the cards chosen by the players must remain secret, and only the winner of each round is revealed. This secrecy is expected to add depth to the game by emphasizing the strategy of reading an opponent’s hand. As designed, the game requires a dealer to secretly calculate the sum of the cards and announce only the winner. In this paper, instead of relying on a human dealer, we use card-based cryptography to virtually fulfill the dealer’s role. In other words, we design an ‘unconventional’ computation protocol that allows players to securely determine the winner without a dealer using a physical deck of cards.