September’s Hanafuda suit is chrysanthemum. In the exact Koi-Koi card set imported for Japan Almanac, the ninth month uses card IDs 32 through 35: the sake cup, a blue ribbon, and two chaff cards.

The chrysanthemum association is not decorative filler. Kokugakuin University’s Encyclopedia of Shinto identifies Choyo, also called Kiku no Sekku, as the Chrysanthemum Festival held on September 9. Its article connects the date to chrysanthemum-petal wine, longevity wishes, and older seasonal festival practice.

The Sake Cup

The sake cup is the suit’s most consequential card in play. In Koi-Koi’s current ruleset, card 32 is treated as an animal/object card, so it contributes to the animal/object class. It also enables two cup yaku when those house rules are active: moon with cup, and curtain with cup.

That does not mean every ruleset treats the cup identically. The Koi-Koi rules documentation explicitly separates its default behavior from variants, including whether the sake cup also counts as chaff. Japan Almanac follows that same language: the app’s rules are accurate for the app, while broader Hanafuda play may vary.

The Blue Ribbon

Card 33 is a blue ribbon. In Koi-Koi, the blue ribbons in June, September, and October form the Aotan pattern. The ribbon matters visually too: it gives the chrysanthemum suit a cool counterweight to the gold and red of the cup card.

Two Chaff Cards

Cards 34 and 35 are chaff. Chaff cards are easy to underestimate because they are low-value individually, but a Koi-Koi round often turns on accumulation: enough small cards become Kasu, and a quiet capture can shift the decision from passivity to pressure.

How We Know

The deck structure comes from Nintendo Museum’s description of Hanafuda as a 48-card, 12-month deck. The specific IDs and Koi-Koi classes come from the Koi-Koi rules repository. Choyo no Sekku context comes from Kokugakuin University. Where Koi-Koi marks a rule as variable, this article marks it as variable too.

Sources

  1. Try Playing Hanafuda!, Nintendo Museum. Accessed 2026-09-01. Used for the 48-card, 12-month Hanafuda structure and Nintendo Museum workshop context.
  2. Choyo, Kokugakuin University Digital Museum, Encyclopedia of Shinto. Accessed 2026-09-01. Used for Choyo no Sekku, chrysanthemum wine, and festival history.
  3. Koi-Koi - Rules & Variants, Koi-Koi repository. Accessed 2026-09-01. Used for the current Koi-Koi ruleset and house-rule disclosure.
  4. Cultural Reference - Hanafuda & the Twelve Months, Koi-Koi repository. Accessed 2026-09-01. Internal topic map only; not treated as external factual authority.

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