Sen Sōshitsu XV (十五代千宗室) refers to the 15th generation head (iemoto) of Urasenke, one of the most widely known schools of Japanese tea. Hōunsai (鵬雲斎) was a religious appellation that he received in 1949 from his Zen mentor, and it is the name that he generally is known by to distinguish him as the 15th Sen Sōshitsu. His son succeeded him as the 16th generation head of Urasenke, and inherited the name Sōshitsu, in December 2002. With that, Sen Sōshitsu XV discontinued his own use of the name Sōshitsu. He adopted the name Genshitsu (玄室) to use instead, and thus has officially gone by the name Sen Genshitsu since then.