When the seventh generation head of the Hisada family, Kokosai Soya, passed away, he was survived by his second son, Tatsuzo; however, because his son had been born only the previous year, Muneyoshi SEKI (関宗厳) was adopted as his guardian, and became the eighth generation Munetoshi.
7代皓々斎宗也が没した際に次男達蔵が残されていたが、前年生まれたばかりのため後見人として関宗厳を養子に迎え8代宗利とした。