The fourth generation Soshitsu HANSO identified himself as 'Genshitsu' before succession to the name of Soshitsu, which started when the twelfth Soshitsu JIKISHO identified himself as Genshitsu upon retirement.
「玄室」と言う名は、千家4代目の仙叟宗室が宗室襲名前に玄室と名乗っており、この事に因んで12代直叟宗室が隠居した際に玄室を名乗った事に由来する。