Tsuuiisou

Conditions

• Every tile in the hand must be an honor tile (winds: 1z-4z, or dragons: 5z-7z)
• No suited tiles (characters, circles, or bamboo) are allowed
• The hand can be open — calling pon on honor tiles is allowed
• The hand will necessarily be all triplets (or kans) plus a pair, since sequences cannot be formed with honor tiles
• Tsuuiisou inherently overlaps with toitoi and multiple yakuhai, but the yakuman value supersedes all other han

Strategy Tips

• There are only seven types of honor tiles (four winds and three dragons) with four copies each, giving 28 total honor tiles in the game. You need 14 of them for your hand, which means you need half of all honor tiles in play — a very tall order.
• If your starting hand has four or more honor pairs or triplets, tsuuiisou becomes a real possibility. The key is drawing or calling enough honors before other players snap them up for their own yakuhai melds.
• Tsuuiisou often overlaps with shousuushii or daisangen. If you fall short of collecting all the wind or dragon triplets you need, check whether your hand qualifies for one of those yakuman instead.