Dice games in Japan have their roots in ancient Asia. Cubic dice (saikoro, サイコロ) arrived in Japan from China and Korea around the 6th century, alongside Buddhism and writing. The Nihon Shoki (Chronicles of Japan, 720) already mentions Sugoroku (双六), a board game using dice, played at the imperial court. The popularity of dice games was such that Emperor Tenmu banned them by decree in 689 — the first known gambling prohibition in Japanese history. Knucklebones (sheep ankle bones) also served as divination tools in early Shinto, linking chance to the sacred. Traditional Japanese dice are distinguished by a red mark on the 1 face (ichi), symbolizing the rising sun and good fortune.
Cho-Han Bakuchi (丁半博打) emerged as the game of choice in Edo period Japan (1603-1868), under the Tokugawa shogunate. The term bakuchi combines the kanji 博 (baku, game) and 打 (uchi, strike), evoking the dealer's gesture of forcefully placing the bowl on the tatami. Despite repeated bans by the bakufu (shogunal government) — notably the edicts of the Kyōhō era (1716-1736) under Shogun Yoshimune Tokugawa — the game thrived in the gray zones of post-station towns (shukuba-machi) along the Tōkaidō and in pleasure quarters (yūkaku) like Yoshiwara in Edo. Underground gambling houses (tobaku-ba, 賭博場) welcomed declassed samurai (rōnin), merchants, and artisans. Cho-Han became the most popular game among the common classes thanks to its absolute simplicity: no skill required, just the thrill of pure chance.
Cho-Han is intimately linked to the history of the bakuto (博徒), professional itinerant gamblers who organized underground games throughout Japan. These bakuto are the direct ancestors of the modern yakuza — the word yakuza itself reportedly comes from the card game Oicho-Kabu, where the combination ya-ku-za (8-9-3 = 20, or zero points) designates the worst possible hand, hence the figurative meaning of "good for nothing." The central figure in Cho-Han was the tsubo-furi (壺振り, "the one who shakes the bowl"), a dealer who traditionally wore his kimono open to the waist to prove he was not concealing loaded dice in his sleeves. The house collected a commission called terasen (寺銭, literally "temple money"), typically 5 to 10% of bets, the sole source of profit in this perfectly fair game. The bakuto developed a strict code of honor (jingi, 仁義) and oath rituals (sakazuki, exchange of sake cups) that endure in contemporary yakuza protocol.
Mathematically, Cho-Han offers perfect symmetry. Two six-sided dice produce 36 possible combinations (6 × 6), of which exactly 18 yield an even sum (Cho) and 18 an odd sum (Han), giving a rigorously equal probability of 50% for each outcome. The sum of 7 is the most frequent with 6 combinations out of 36 (16.7%), while the extremes — 2 (snake eyes, 1+1) and 12 (boxcars, 6+6) — have only a 1 in 36 chance each (2.8%). Unlike European roulette (2.7% house edge thanks to the zero) or American craps (1.41% on the Pass line), pure Cho-Han confers no mathematical advantage to the house, which profits solely from the terasen. Japanese mathematician Seki Takakazu (関孝和, 1642-1708), considered the "Japanese Newton," independently developed combinatorial calculus in his Hatsubi Sanpō (1674), techniques that allow rigorous analysis of dice game probabilities like those in Cho-Han.
Cho-Han has become an unmistakable cultural marker of Japan in world fiction. In cinema, Cho-Han scenes punctuate the yakuza films (ninkyo eiga) of Toei Company from the 1960s-70s, featuring iconic actors like Ken Takakura in the Abashiri Bangaichi series (1965-1972, 18 films). Director Takeshi Kitano immortalized the game in Zatoichi (2003), where the legendary blind masseur detects loaded dice through his supernatural hearing — the film won the Silver Lion at the Venice Film Festival. In the manga Kaiji (Fukumoto Nobuyuki, 1996), gambling games including Cho-Han are at the heart of the plot, adapted into anime (Madhouse, 2007) and live-action films (2009, 2011). Naruto features Tsunade, the "legendary sucker" (densetsu no kamo), playing Cho-Han with proverbial bad luck.
In contemporary Japan, traditional Cho-Han has been largely overtaken by pachinko (approximately 7,800 parlors in 2023, down from a peak of 18,000 in 1995) and horse racing through the JRA (Japan Racing Association, 3 trillion yen in annual revenue). The dice game survives nonetheless at festivals (matsuri) and historical reenactments, notably at the Jidai Matsuri in Kyoto and in Edo period museum villages such as Noboribetsu Date Jidaimura in Hokkaido. Online casinos have given Cho-Han a second life, offering it alongside Chinese Sic Bo in "Asian games" categories. Japan legalized land-based casinos with the Integrated Resort (IR) Implementation Act of 2018, and the MGM Osaka complex, planned for 2030, could include traditional Japanese gaming tables. Above all, SEGA's Yakuza / Like a Dragon video game series, which has sold over 21 million copies worldwide (2024), remains the primary vehicle for introducing Cho-Han to new generations around the globe.