The Atomic Bomb Game

August 6, 1945. Hiroshima, Japan. 8:15 a.m. At the exact moment the uranium bomb "Little Boy" detonated over the city, two of Japan's strongest professional Go players were seated at a board in a suburban dormitory, replaying the first 106 moves of their adjourned game. They had not yet placed a single new stone for the third day of play. What happened next became one of the most extraordinary stories in the entire history of board games.

A Title Match in Wartime

The 3rd Honinbo title match of 1945 pitted defending champion Hashimoto Utaro (White) against challenger Iwamoto Kaoru (Black). Both men were 7-dan professionals at the peak of their powers. The Honinbo was (and remains) one of the most prestigious titles in Go, Japan's ancient game of territory and strategy.

Game 1 had been played in late July in central Hiroshima. For Game 2, police had insisted the match be moved to a safer suburban location, the employees' dormitory of a coal company in Yoshimi-en, roughly 5 to 10 kilometres from what would become ground zero. Leaflets warning of a powerful new bomb had been dropped over the city; the authorities were taking no chances. The game was scheduled across three days: 4, 5 and 6 August 1945.

8:15 a.m.: The World Changed

On the morning of the third day the players and officials (including renowned referee Segoe Kensaku) gathered as usual. They replayed the adjourned position onto the board. At 8:15 a.m. the sky over Hiroshima turned white. The blast wave reached the suburban venue seconds later. Windows shattered. Flying glass injured several people present. Hashimoto Utaro was physically blown off his feet. The building was damaged but, because it stood several kilometres from the hypocentre, it did not collapse.

In the stunned silence that followed, the players and officials realised something catastrophic had occurred. Wounded survivors soon began streaming past the venue from the devastated city centre.

"We Will Finish the Game"

What they did next still astonishes people who study the history of sport and games. After assessing the damage and treating the immediate injuries, the players and officials cleaned the room as best they could. They reassembled the board position from memory. Then, after a brief lunch break, they resumed play. They played through the afternoon and into the evening, completing the game that same day under conditions no player in history has ever faced.

Result: Hashimoto Utaro (White) won by five points. The full game record runs to 240 moves.

The Match and Its Aftermath

The 1945 Honinbo series was later completed despite the chaos of Japan's surrender and the early postwar period. It finished 3 to 3. In a three-game playoff held in 1946, Iwamoto Kaoru defeated Hashimoto to claim the title (becoming Honinbo Kunwa).

Both men went on to long and distinguished careers. Iwamoto later became a 9-dan and one of Go's greatest international ambassadors, travelling the world to spread the game. Hashimoto founded the Kansai Ki-in and remained a central figure in Japanese Go for decades.

Why This Story Endures

The "Atomic Bomb Game" is not famous because of brilliant tesuji or dramatic yose. It is remembered because two professionals, in the middle of one of history's greatest tragedies, chose to honour their craft and their opponent by finishing what they had started. In a world that had just witnessed the birth of the nuclear age, they demonstrated something profoundly human: the instinct to continue, to maintain dignity, and to treat even a game with the seriousness it deserves.

The position on the board at 8:15 a.m. on 6 August 1945, after move 106, has been preserved in game records and visualised in modern reconstructions. The story itself is told in Go clubs and history books around the world as a quiet but powerful testament to professionalism under unimaginable pressure.

Primary sources for this account include contemporary records of the Nihon Ki-in, reports by the game recorder Miwa Yoshiro, and later compilations by Go historians (notably detailed entries on Sensei's Library and in standard references to the Honinbo title).