Waka poems were a popular art form in the Heian period, enough that the famous poet Fujiwara no Sadaie and Emperor Go-Toba sought to put together a selected collection of chosen verses.
Emperor Tenji, who was active 
during the Taika reforms,
El emperador Tenji, activo
durante las Reformas Taika,
Imperador Tenji, que estava na
ativa durante as reformas de Taika,