- Distinction: Ashina, Date retainer
- Sons: Inawashiro Moritane, Inawashiro Munekuni, Inawashiro Moriaki
Morikuni was a son of Inawashiro Morikiyo. He at first served the Ashina of the Aizu district of Mutsu province and held Inawashiro castle. A general of some ability, he halted Date Masamune's 1585 campaign against the Ashina at Hibara. In 1589, after growing discord between the Inawashiro and Ashina Yoshihiro, Morikuni approached Date Masamune through the offices of Haneda Naokage (a retainer of Date Shigezane). Morikuni then rebelled against the Ashina and joined Masamune's campaign into Aizu (which saw the Ashina army defeated at Suriagehara and the fall of the Ashina's Kurokawa castle). Masamune showed his gratitude to Morikuni by allowing him to adopt the Date family crest as his own. He his eldest son died not long after the fall of the Ashina family and so Morikuni was succeeded by his second son, Inawashiro Munekuni.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005