In 1709, Meijin Soukei V called upon his son Sougin (大橋宗銀) to represent the Oohashi main house at Edo Castle for the Castle Shogi. That same year, Itou Intatsu (伊藤印達), son of Itou Souin II, would also participate for the first time. Intatsu was just 11 years old and Sougin was 15, but they were both already 5-dan, and won their games against Oohashi Souyo III (right lance handicap) and Itou Souin II (bishop handicap) respectively. As young geniuses directly descended from different shogi houses, their paths would cross sooner rather than later.
The two prodigies began a fateful match in the 10th day of the 10th month in 1709, before the Castle Shogi took place. Originally supposed to last 10 games, the contest ended up spanning a massive 57 games across one and a half years, lasting through the first two months of 1711. This epic battle would come to be known as the 57-game match (五十七番勝負). The match started with even games, but under the sashikomi handicap system Sougin had alternate between accepting lance handicap and even games against Intatsu. Intatsu pressed his opponent further, forcing the match to change phases into a lance handicap every game, then alternating bishop and lance handicaps. When the match finally ended, Intatsu was giving a bishop handicap every game while leading in score 36 to 21, an overwhelming display of strength.
The players would tragically not have a chance to continue their rivalry. Intatsu died of illness in 1712 aged just 14. In 1713, Meijin Soukei V would succumb to illness aged 78, while Sougin passed soon after at 18, just days after becoming the 6th head of the Oohashi main family. The final confrontation between these two prodigies was a Castle Shogi game in 1711, an even feint Ranging Rook versus Static Rook game won by Intatsu as gote.
The epic yet tragic match brought some amazing games to the shogi world, yet also left a void in the wake of its conclusion. Yet again the Oohashi house was brought to the brink of extinction; this time a successor was found in Oohashi Soukei VII, although his provenance is unclear due to the pressing circumstances of the search. Not much is known of him, but he was an acceptably strong player for the house, attaining the rank of 7-dan, but retiring at the early age of 37 in 1724.
And the other void to fill was that of Meijin, which would go to Soukei V’s old rival, Itou Souin II.