Tofu Kingdom is a deduction game involving seven characters. The player assuming the role of Prince Mochi asks each of the other players one question, then guesses which player plays the role of Princess Tofu, the love of Prince Mochi. When answering Prince Mochi's questions, the other players must either lie or tell the truth based on the cards they hold.

The player who Prince Mochi chooses to be Princess Tofu (whether rightly or wrongly) wins the round and receives the number of points specified on their role card. The player who first accumulates 7 points wins.