Gyosei (御製)
Gyosei refers to documents (aside from decrees), poems and paintings that have been personally written or created by emperors or royal family members. Within Japan, the term gyosei is generally used to refer to waka (poems) composed by the emperor.
Exemplary works of gyosei include the 'Shogyojo' (writing done by the emperor's hand) by Taiso (Tang tai zong), that was engraved on the Daiganto at the Daijion-ji Temple. In Japan, gyosei is an honorific expression used in reference to the emperor, Imperial Family and other royalties.