I have added another post for episode 2 with more historical notes, available here:
http://fungafufu.wordpress.com/2011/...-the-tea-room/
In particular, the evidence we`re given in episode 2 leads me to believe that Furuta Sasuke is actually based in part on Furuta Oribe, who was the founder of the Oribe school of the Japanese tea ceremony - see
http://en.wikipedia.org/wiki/Furuta_Shigenari
Most notably, Furuta was also married to Nakagawa Kiyohide's younger sister, and was also a contemporary of Sen no Rikyū and became Rikyū's successor after the old tea master committed seppuku.