Yoshitatsu Saito was Dosan Saito's adopted son.
Yoshitatsu was the son of Yoshiyori Toki and was adopted by Dosan Saito. When his father planned to disinherit him, he went to war and defeated him at Nagaragawa. The battle of Nagaragawa was fought across the Nagara river. Yoshitatsu died of leprosy.
- Nobunaga Oda (in law)