Prince Morinaga or Moriyoshi (1308 – August 12, 1335) was a son of Emperor Go-Daigo and Minamoto no Chikako executed by Ashikaga Tadayoshi in 1335.
When Morinaga was 18, Go-Daigo had him named the head abbot of the Enryakuji temple on mount Hiei.
When Go-Daigo's attempt to seize power in 1331 failed (the Genko War), Morinaga fled Enryakuji to the province of Kii, meeting up with Kusunoki Masashige. They tenaciously defended the small fortress of Akasaka before finally being forced to withdraw.
He then moved to Mount Yoshiro.
Masashige's heroics defending Chihaya, together with Morinaga's efforts to rally troops, brought a large number of warriors to the loyalist cause. By 1333, Ashikaga Takauji and Nitta Yoshisada had joined the cause. The Hojo shogunate was soon destroyed.
Restored to the throne, Go-Daigo started the Kemmu Restoration. After refusing to appoint Ashikaga Takauji to the post of seii taishogun, he made the double mistake of giving the title to his sons Prince Morinaga and Norinaga, two civilians, thus alienating Takauji and the warrior class, who felt he, as a military man and a descendant of the Minamoto, should have been shogun instead.
Takauji made false charges that Morinaga was planning to overthrow his father, and forced Go-Daigo to hand him over. Morinaga was then sent to Takauji's brother Tadayoshi in Kamakura, and was imprisoned in a cave near Kamakura for eight months.
A rebellion by the remnants of the Hōjō forced Tadayoshi to retreat from Kamakura. Being unable to take Morinaga with him, Tadayoshi had him beheaded on July 23,1335.
The shrine Kamakura-gu, built around the cave where Prince Morinaga was imprisoned, was dedicated to him by Emperor Meiji in 1869.