Modern riichi / yonma

Assessment

Confidence

documented a published ruleset or rule description exists and is cited

Evidence

conflicting sources disagree materially, or one source contradicts itself

Cross-comparison

What each source was read to say, set side by side. The numbers are the sources above.

• [1] discards placed in orderly rows
• [2] length 2 rounds, dead wall 14
• [3] names the four-player game yonma (四麻) against the three-player sanma. Dates the modern riichi variant to the 1960s, with the explosion in popularity after 1969 and online play from Tenhou in 2007. It does not date red fives to 1970 as the chart does
• [15] standardised in Japan and South Korea, prevalent in video games, with riichi and dora as its unique highlights and discards arranged by order in front of each player
• [16] THE CHAIN IS INCOMPLETE: lists seven Amano rulesets — 1952 Hochi, 1957 Tokyo, 1958 Unified, 1963 Olympic, 1967 Modern, 1971 New modern, 1978 New hochi. The chart carries only the first, second and fifth. The chart's 1970 date for this node sits beside Amano's 1971 New modern rules, which it does not mention
• [17] Gives Amano's 1967 modern rules as the origin of rounding fu to ten, bazoro, oka and ura dora, and puts kan dora and akadora among later additions it calls inflation, undated. Says riichi has 'largely overshadowed' arushiiaru, and that the Japan Mahjong Federation accepted it as a second approved variant in 2016
• [4] No date for red fives. Says there is no universal authority for riichi in Japan or abroad, that each parlour and league sets its own rules, and that M.League has run since 2018
• [5] Says red dora were long held to have been devised in Kansai around the 1970 Osaka Expo, but that a manga feature in Kindai Mahjong Original of September 2004 established by interview that the Osaka firm Mizuno Maruichi first made two red fives of circles for the 1964 Tokyo Olympics. Quotes a 1974 tactics book by Ōkuma Hideo on red threes, and red fives of circles, as dora 'west of Kansai'
• [6] Two accounts of the first red tile: devised for the 1970 Osaka Expo, after its cherry-blossom emblem, and first used in Kansai bū mahjong; or devised for the 1964 Tokyo Olympics, after the rings. Asami first judged the Expo account the stronger, then corrected it: Kindai Mahjong vol. 472 (September 2004) found that Mizuno Maruichi of Osaka made the first red fives of circles in 1964, for the Olympics, and asked the tax office not to charge playing-card tax on the extra tiles. Sets with four red tiles have two fives of circles because the first ones did
• [7] Sets the League's official rules beside the WRC rules, WRC-R (the WRC rules with red fives) and M.League's rules 'for reference'
• [9] The M rule follows M.League's rules, liability payments included
• [11] First written in 2013 by Sylvain Malbec from the rules of the EMA, 101, the JPML, the Korean Mahjong League, Mu, NPM, RMU, Saikouisen and the USPML; revised for each championship
• [12] First edition 2008, for the first European Riichi Championship in Hannover; revised in 2012 to be closer to Japanese rules, in 2016 to be closer to the WRC's, and in 2025
• [13] Change log: 2007-03-01 two rules dropped; 2007-07-17 the red five of circles cut from two to one; 2007-11-29 kuikae banned; changes to 2022
• [18] Lists the mahjong parlour among licensed amusement businesses (art. 2(1)(iv)); its play fees are held to national standards (art. 19), and it may not give prizes by result (art. 23(2))
• [19] Dates mahjong in Japan to Kansai about 1921, a first boom in Kanto from 1924 and a second after the war; studies the strategy literature from the 1970s on. Not about rules
• [20] Says 1964 is often given as the origin of red tiles, but was rather when sets with two red fives of circles spread: red dora were around before, and he has heard of rules with tiles other than fives red. Reproduces a panel from まあじゃんほうろうき (Kindai Mahjong Gold, 1989-94) showing red dora uncommon outside free parlours, and dates their becoming the norm to the online game 麻雀格闘倶楽部 (2002), red fives by default. Ippatsu and ura dora were already in the first Famicom mahjong game (1983)

Reading it

The game is not in doubt. The chart's date for its defining detail is wrong, and the detail is optional. Every source agrees on the game: 136 tiles, a 13-tile hand, han and fu, one yaku to win, riichi and dora. The chart dates red fives to 1970, but none of the four sources it cites for this node gives a date. 1970 is the Osaka Expo account, which Japanese Wikipedia says was long believed and which Asami Ryō, its source, retracted. Kindai Mahjong found in September 2004 that the Osaka maker Mizuno Maruichi made the first red tiles, two red fives of circles, for the 1964 Tokyo Olympics. Nemata (2023) reads 1964 as when such sets spread rather than when red tiles began. Asami and Wikipedia name the magazine differently, and the issue itself is wanted. One red five in each suit came later: Tenhou played two red fives of circles until July 2007, and Nemata dates red fives becoming the norm to online play after 2002. Nor do red fives define the modern game. They are in M.League's rules, Tenhou's and RMU's M rule, but not in the official rules of the JPML, NPM or RMU, nor in the WRC's, nor in the EMA's, which say outright that they are not used. The professional rules also differ over ippatsu, ura dora, kiriage mangan and starting points. No law sets rules of play: the Amusement Business Act licenses the parlour.

Looked for, not found

• Rulebook Single-author rule and strategy books are many and in print. The National Diet Library lists one on red-dora strategy (Doi Yasuaki, 2010). None found online dates red fives, and the leagues' own rules are cited instead.
• Forum Zhihu answers on the red fives of circles relay Asami's 1964 account. Zhihu, Reddit and BoardGameGeek refuse automated readers, and Yahoo! Chiebukuro questions were found but not read.
• Organisation The leagues' and federations' pages were read for their rules, cited above. The WRC's own rules overview dates the championship to a 2013 agreement between TriNitroTiles of Paris and the JPML.

Known, not yet read

Sources that look worth having but could not be read for this entry. If you can reach one, it can be read and added. Every variant’s list is gathered on Missing sources.

• Official rules Saikouisen 最高位戦日本プロ麻雀協会, official rules — One of the large Japanese professional leagues, and one of the nine rulesets the WRC rules were drawn from.
  Where: https://www.saikouisen.com/. Tried: The research environment's gateway answered 502, and a second fetcher got 503 (2026-10-06).
• Official rules Korean Mahjong League 한국마작연맹, rules — The riichi body in South Korea, and one of the nine rulesets the WRC rules were drawn from.
  Where: https://kml.or.kr/. Tried: 403 to automated requests (2026-10-06).
• Journalism Kindai Mahjong 近代麻雀, vol. 472 (September 2004), the まんトリ feature (story Fukuchi Makoto, art Ōtsubo Maki) — The interview finding that Mizuno Maruichi made the first red tiles in 1964, on which Asami Ryō and Japanese Wikipedia both rely. They name the magazine differently: 月刊近代麻雀 and 近代麻雀オリジナル.
  Where: Print: Takeshobo, September 2004.. Tried: Print only.
• Historical Ōkuma Hideo 大隈秀夫, 『マージャン金言集』 (Kōbunsha, 1974), pp. 162-163 — Japanese Wikipedia quotes it on red threes, and red fives of circles, as dora 'west of Kansai': the earliest dated printed mention of red tiles found.
  Where: https://ndlsearch.ndl.go.jp/books/R100000002-I000001294883. Tried: Print only.
• Historical Amano Daizō 天野大三, 『「現代ルール」による図解麻雀入門』 (Gotō Shoin, 1971) — The designer's own book on his modern rules, published the year after the chart's date. Whether it has red fives would settle what 'modern riichi, 1970' can mean.
  Where: https://ndlsearch.ndl.go.jp/books/R100000002-I000001297056. Tried: Print only.
• Journalism Matsutani Minoru, "Mah-jongg ancient, progressive", Japan Times, 15 June 2010 — English Wikipedia's source for 7.6 million players and about 8,900 parlours in Japan in 2008.
  Where: https://www.japantimes.co.jp/news/2010/06/15/reference/mah-jongg-ancient-progressive/. Tried: Paywalled: the article body is not in the page, and a second fetcher got 402 (2026-10-06).
• Scholarship Ebashi Takashi 江橋崇, 『牌が語る麻雀の歴史：野口恭一郎と麻雀博物館設立の物語』 (Goma Books, 2023) — A historian's account of mahjong through its tiles and of the Mahjong Museum's founding: the likeliest source to date red tiles from surviving sets.
  Where: https://ndlsearch.ndl.go.jp/books/R100000002-I033081901. Tried: Print only.
• Collection Mahjong Museum 麻雀博物館, 『麻雀の歴史と文化：麻雀博物館図録』 (Takeshobo, 2005) — The museum's catalogue of its collection, which should show when red tiles appear in Japanese sets.
  Where: https://ndlsearch.ndl.go.jp/books/R100000002-I000007942516. Tried: Print only.
• Scholarship Kuroki Masaki 黒木真生, 『麻雀プロ団体分裂と闘争の歴史』 (Takeshobo, 2026) — A history of the professional organisations' splits, which is the history of why their rules differ.
  Where: https://ndlsearch.ndl.go.jp/books/R100000002-I034616800. Tried: Print only.
• Encyclopedia Namu Wiki, 리치마작 (riichi mahjong) — The fullest Korean-language account of riichi and of how it is organised in Korea.
  Where: https://namu.wiki/w/%EB%A6%AC%EC%B9%98%EB%A7%88%EC%9E%91. Tried: 403 to automated requests, as were the riichi pages of thewiki.kr and Libre Wiki (2026-10-06).
• Encyclopedia Baidu Baike, 日本麻将 (Japanese mahjong) — The mainland Chinese encyclopedia's account of riichi.
  Where: https://baike.baidu.com/item/%E6%97%A5%E6%9C%AC%E9%BA%BB%E5%B0%86. Tried: 403, and the connection was cut (2026-10-06).

Where it was searched

Every place the search checklist names for this variant’s languages, and what each gave, including nothing. The last full pass was on 2026-10-06.

Names searched: Japanese リーチ麻雀, 立直麻雀, 日本式の麻雀, 四人麻雀, 四麻, リーチマージャン; English riichi mahjong, Japanese mahjong, riichi, riichi mah-jong, reach mahjong, yonma; Chinese 日本麻將, 日本麻将, 日本麻雀, 立直麻將, 立直麻将, 日麻; Korean 리치 마작, 리치마작, 일본 마작, 일본식 마작, 일식 마작.