After Toshizo HIJIKARA, who was leading the Shinsengumi, died in battle on June 20, 1869, the Shinsengumi members staying in Benten Daiba (Cape Benten Battery) presented a letter of obedience to the new government with the name of Soma at the head of the letter as Commander, which finally closed the curtain on the history of the Shinsengumi.
明治2年5月11日、新選組を統率していた土方歳三が戦死すると、弁天台場の新選組は相馬を隊長として恭順の書状に名前をしたため、新選組の歴史に幕を引いた。