It can be estimated that those characters refer to the following: 'Kanotomi' means Tenmu 10th year (681), and 'Okume' means the name of Prince Otomo's sister, Okume-no-miko (Princess Okume).
「辛巳年」は天武10年(681)、「大来」は大友皇子の姉の大来（伯）皇女の名と推定できる。