Kani Saizô was originally a vassal of the Saitô in Mino province. When Saitô Tatsuoki was defeated by Oda Nobunaga, Saizô joined the Shibata clan, which he later left to serve Akechi Mitsuhide. After Mitsuhide's defeat at the Battle of Yamazaki, he joined Oda Nobutaka until Nobutaka, too, was killed (1583). Saizô eventually joined Toyotomi Hidetsugu, and then, following Hidetsugu's fall, went to serve Maeda Toshiie. Eventually, he ended up with Fukushima Masanori, under whom he would serve at the Battle of Sekigahara. He is best remembered for his taking of 16 heads at Sekigahara - probably the most for any one single warrior at that battle. Rather than bring the heads back to camp one by one, Saizô marked them as his own by stuffing their mouths with bamboo grass. It is said that upon hearing of his deeds at the post battle gathering, Tokugawa Ieyasu nicknamed him 'Sasasaizô' - Bamboo grass Saizô.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005