Son of Asonuma Hirotsuna, of the Fujiwara-branch Ashikaga lineage. His father was granted the jitō stewardship of Tōno in Mutsu's Hei district by Minamoto no Yoritomo for service in the 1189 Oshu Campaign. Chikatsuna is said to have come down to Tōno and, around the Kenpō era (1213-1219), built Yokota Castle on Mt. Gomadō as his seat of governance. His descendants ruled Tōno as the Asonuma clan into the Sengoku period.

A settler who inherited his father's stewardship and put down roots in Tōno.

Laid the foundation of the Tōno Asonuma line, which endured into the Sengoku period.