Minoru YOSHINAGA who interprets the Emperor Kotoku's poem to mean that some man has stolen his wife, based on the assumption that 'a chess piece' is the metaphor of Hashihito and that in the ancient times 'to see someone' implies to love someone, says that Hashihito no Himemiko had an incestuous relationship with her brother, Naka no Oe no Oji.
しかし、うえの歌の「駒」が間人を譬喩しており、古代の「見る」が恋愛の直結するものであることから、自分の妻をほかの男に見られたの意に理解し、中大兄との近親相姦の関係を説く吉永登のような見解もある。