Of the five Meijin (and one posthumous Meijin) from 1653 to 1761, four were from the house of Itou and one was related by blood (fourth Meijin Oohashi Soukei V, son of third Meijin Itou Soukan I). The Itou family had clearly dominated in strength, but never more so than in the later half of this period, beginning with one man and his family.
Itou Souin II (伊藤宗印, unknown-1723), the adopted son of third Meijin Itou Soukan I, became the fifth Meijin in 1713. Born as Tsuruta Gen’an (鶴田幻庵), he was found to be a strong shogi player and entered the Itou house to avert its premature end, as Soukan I’s only son had been given to the Oohashi main house in 1664.
Souin II’s gifted tsumeshogi collection was the 100-problem Shogi Yuuryaku (将棋勇略) some time after 1700, but he is also known for the classic 100-problem manual Shogi Seimyou (将棋精妙), published posthumously. This makes him one of just two players in the Edo period to leave behind 200 tsumeshogi problems, the other being Kuwabara Kiminaka 4-dan (桑原君中) later in the 18th century.
The strongest family
Like his adoptive father, Souin II had shown talent at a young age, and passed this talent on to his five children. Furthermore, he would regularly meet with his children to guide them and hone their skills; all five would become high-dan shogi players. Intatsu had died young but had attained 5-dan at the age of 11; Inju would later become the 7th Meijin Itou Soukan III; Souju would later become 8-dan and the eighth head of the Oohashi main house Oohashi Soukei VIII; Kanjo would become 7-dan; and the youngest son Kanju would later become 8-dan, granted the title of Meijin posthumously, and remain famous as a pioneering tsumeshogi composer even 300 years later.
It would not be an exaggeration to claim that Souin II had raised the strongest shogi family in history.
Souin II presided as Meijin through his 60s, playing his last Castle game in 1722 against Oohashi Soumin (later Oohashi Souyo IV), giving a bishop handicap and losing. He passed away in 1723. His tombstone is located today in Honpouji Temple (本法寺) in Sumida Ward, Tokyo.