Fukushima Masanori
, also known as Kani Yoshinaga (可児吉長), was a Japanese samurai of the late Sengoku era through early Edo era, who served various lords before coming into the service of the Tokugawa clan. Saizō was originally a junior retainer under the Saitō clan, then switched to the Oda clan. Still later, he served under the Tokugawa. In the early Edo era, Saizō joined Fukushima Masanori during the latter's move to the Hiroshima Domain, and died in 1613.