This hanafuda game is a Koi-koi variant, but with many Yaku from the 2-player Toppa retained. It is attested to be played in the Kushiro Subprefecture in Hokkaido.
This game is played by 2 to 4 people, although only 2 people participate in a round at once.
Just like in Koi-koi, card points are not counted in this game. Points are obtained only by forming Yaku.
A standard 48-card hanafuda deck is used. Also prepare chips for scoring, and all player must have equal number of chips at the beginning. 1 “yaku” = 1 chip. (If playing for money, decide first the exchange rate per “yaku”.)
¶ Choosing the Dealer
The attested method of selecting the first dealer is as follows: Shuffle the deck, and cut it into two piles face-down. Each player draws 1 card from either of the two piles. The player with a card of the earliest month becomes the dealer for the first round.
¶ Distributing the Initial Cards
The method is similar to 2-player Toppa; Ten (10) cards are distributed to each player, and eight (8) to the table, and the remainder of the deck is placed face-down to form the draw pile.
If four cards of the same month are dealt on the field, then a misdeal is declared, and the dealer reshuffles and deals again.
If four cards of the same month are dealt on a player’s hand, then the player may place all four cards face down on the table. Another player then chooses one card and switches it with the top card of the deck. All four cards go back to the player’s hand.
¶ Checking for Teyaku
After the cards are dealt, each player checks if they possess any sets in hand called teyaku [手役 - てやく].
Since Willow 
cards are not automatically considered Chaff in a Teyaku, forming a Teyaku is rare.
| Value (in “yaku”) | Name | Description |
|---|---|---|
¶ Group A: Set Teyaku |
||
| 1 | Three Pairs さんぞくいち [sanzokuichi] |
Three pairs of cards- a pair being two cards from the same month. |
¶ Group B: Chaff TeyakuNote: For the purposes of these teyaku, each Willow card is treated according to its card type; Willow cards are not automatically treated as Chaff cards. |
||
| 1 | One Ribbon 短一 [他のさらし, tan’ichi] |
One Ribbon card, seven Chaff. |
| 1 | One Animal 十一 [他のさらし, toichi] |
One Animal card, seven Chaff. |
| 1 | One Bright 光一 [他のさらし, pikaichi] |
One Bright card, seven Chaff. |
| 1 | Empty Hand 総ガラ [そうがら, sō gara] |
Eight Chaff cards. |
¶ Join-in / Drop-out Phase
Since only 2 players can participate during a round, players must decide if they want to participate (or “join in”), or wait until the next round (or “drop out”).
After players have seen the cards dealt to them, each player declares to Join-in/Drop-out, starting from the player to the dealer’s right. (This is probably to eliminate dealer’s advantage.)
Only two players can join in per round. Once two players have decided to join in, the remaining players who haven’t decided automatically cannot participate (or “forced-out”).
Unlike in Hachi-hachi, there’s no fee for Dropping out, nor are there any compensation for Forced-out players.
If there are only two players to begin with, then the above Join-in/Drop-out phase is skipped.
¶ Exposing the Teyaku
Once two players have joined in, if either of the players has a Teyaku, they may choose to expose it.
What happens after exposing a Teyaku is not explained; Decide first whether to stop the round and claim the points, or to claim the points and continue playing before starting the game. (NEEDS MORE DOCUMENTATION)
¶ Gameplay (Koi-koi mechanics)
The gameplay is similar to Koi-koi in that as soon as a Dekiyaku is formed, the player who has formed the Dekiyaku has a choice whether to stop the round and claim the points, or continue the round in hopes of forming another Dekiyaku.
Also, if a player continued the round, and the opponent then formed a dekiyaku and stopped the round, then the player’s Dekiyaku is forfeited.
To continue the round, declare “Iku!”.
To stop the round, declare “Yoroshii!”.
¶ Dekiyaku
All Dekiyaku stack except for Dekiyaku in the Bright Yaku group (only the highest scoring Bright Yaku is counted).
| Value (in “yaku”) | Yaku Name | Composition |
|---|---|---|
¶ Bright Yaku |
||
| 3 | Five Brights 五光 [ごこう, gokō] |
     |
| 2 | Four Brights (Dry 4) 本四光 [ほんしこう, honshikō, ‘real four brights’] |
|
| 1 | Rainy Four Brights 四光 [しこう, shikō, ‘four brights’] |
plus 3 of: |
¶ Ribbon and Willow Yaku |
||
| Value (in “yaku”) | Yaku Name | Composition |
| 1 | Poetry Ribbons 菅原 [すがわら, sugawara] |
   |
| 1 | Blue Ribbons 青短 [あおたん, aotan] |
   |
| 2 | Seven Ribbons しょう七 [しょうなな, shōnana, ‘small seven’] |
Any 7 cards consisting of Ribbon cards and/or Willow cards. This yaku is worth 1 extra “yaku” for each additional Ribbon or Willow card. |
¶ Chaff Yaku |
||
| Value (in “yaku”) | Yaku Name | Composition |
| 1 | Chaff カラ [から, kara] |
Any 12 Chaff cards. This yaku is worth 1 extra “yaku” for each additional Chaff card. |