It was in the generation of his children, Sōsa, Sōshitsu and Sōshu, that the three lines of the family—the Omotesenke, Urasenke and Mushakōjisenke—were established, with these three sons, respectively, as their heads of house.
[2] During the years following Rikyū's death, when the Sen family was disbanded and Sōtan's father found shelter with the daimyō Gamō Ujisato in distant Aizu Wakamatsu, Sōtan was able to stay safely at Daitoku-ji temple.
Sōtan arranged for his second son, Ichiō Sōshu, to be adopted into the family of a lacquer ware artisan at a young age.
Eventually, he became heir to the retirement quarters, and the family there came to be known as the Urasenke (rear Sen house/family).
They were Fujimura Yōken (1613–99), Sugiki Fusai (1628–1706), Yamada Sōhen (1627–1708), and Kusumi Soan (1636–1728).