Yasumune UTSUNOMIYA had a older brother, Sadatsuna UTSUNOMIYA who was the sixth family head of the UTSUNOMIYA clan (the eighth from FUJIWARA no Soen) and held the title of Shimotsuke no kami (the provisional governor of Shimotsuke Province).
宇都宮氏第六代(藤原宗円から数えると第八代)、下野守護の宇都宮貞綱の弟である。