Kyū, which means "nine" in Japanese, is a tactical card game in which you win by controlling three nobles at the same time. Each noble favors a different arrangement of cards, such as the longest straight, the most cards of the same color, or as many of the same card as possible.
The deck consists of cards numbered 1-9 in either red or black. Each player starts with cards in hand, along with other cards in a face-up display. Gameplay takes place in phases, with players first swapping a card from the display with one from their hand or drawing from the deck, then discarding. After this phase ends, the nobles issue challenges, going to whoever best satisfies them, although they can be won away from you in the future.
Ideally you can build a hand that's flexible enough to satisfy three nobles during a single challenge...