Additionally, Motohiko IZAWA, a novelist who wrote "Gyakusetu no nihonnshi" ("Japanese History in Paradox"), says in his book that ancient Japanese, under the influence of Chinese Civilization, believed that spirits totally neglected by their decendents would become onryo, which he defines as "the stage before goryo shinko", and that due to the incident of Prince Nagaya and the four Fujiwara sons, the stage developed into a typical Japanese onryo shinko whereby the departed soul of a man who died because of a false charge would become an onryo.
なお、小説家の井沢元彦は逆説の日本史において、古代の日本は中国文明の影響によって、子孫の祭祀の絶えた者が怨霊となるとして、これを「プレ怨霊信仰」と呼び、それが長屋王と藤原四子の事件により「冤罪で死んだ者が怨霊となる」という「日本的怨霊信仰」へと変化したと提唱している。