He was nicknamed "Invincible" after he earned a perfect score for 19 straight wins in the annual castle games.

Shusaku, for example, had a plus score against Ōta Yūzo but still found him a tough opponent, while Shuwa beat him easily.

Only two other people have been given the title "Go Sage" (Kisei) in addition to Shusaku, the others being Honinbō Dosaku (1645–1702) and Honinbo Jowa (1787–1847).

However, Jowa's title was posthumously revoked due to a biased account of his machinations (in the Zain Danso) towards obtaining the post of Meijin Godokoro.

He was born on the island of Innoshima near the town of Onomichi, Hiroshima Prefecture, Japan to a merchant, Kuwabara Wazo.

In the following years, he made steady progress up the ranks, reaching 4 dan in 1844, after which he again returned home for a prolonged period.

He fought back hard, but still by the time of the middlegame, all the people watching the game thought Gennan was winning, except for one, a doctor.

After forcing his main rival and friend Ōta Yūzo to take a handicap, he was generally accepted to be the strongest player with the exception of Shuwa.

The players were Yasui Sanchi, Ito Showa, Sakaguchi Sentoku, Hattori Seitetsu, and Ōta Yūzo.

It was thought as a great achievement, having a tie after taking white, so much that it was used, along with Shusaku's calling up for the castle games, as an excuse to adjourn the match.

This caused controversy in the United Kingdom, as it was felt that preempting the 70th anniversary of the Normandy landings to honour a Japanese person was impolitic.