The head family of the Toshima clan went to ruin in the Muromachi period and the genealogy was restored more than two hundred years later, with confusion in identification of the people, and in recent study, Asatsune was believed to be a son of Aritsune who was described as his son in the genealogy, and their parent-child relationship was reversed.
豊島氏本宗家は室町時代に滅びており、系図はその200年以上後になって復元されたもので、人物の比定に混乱が見られ、近年の研究では朝経は系図では子になっている有経の子と推定され、親子関係が逆転している。