Emperor Kotoku, who is said to have ascended to the throne in 645, and Emperor Monmu, who is said to have ascended to the throne in 696, referred to themselves as Prince Karu before their enthronement.
645年即位とされる孝徳天皇も696年即位とされる文武天皇も、即位前は軽皇子と名乗っている。