Nagasunehiko is a character that appears in Japanese mythology. In "The Kojiki" (Records of Ancient Matters) he is written as Nagasunehiko, but he is also called Tominonagasunehiko as well as Tomibiko. He is portrayed in the scene of Jinmu Tosei (Emperor Jinmu's expedition to the east) as the head of a local ruling family in the Yamato Province area who opposed Jinmu's expedition to the east.
He attacked the invading enemies at Kusaenosaka after Emperor Jinmu arrived at Shirakata no tsu (Bay of Shirakata) in 青雲, Namihaya Province, and the Emperor's older brother, Itsuse no Mikoto, was injured by an arrow during this battle, and later died.
He later fought again, against the Imperial army who killed Yasotakeru and Eshiki. At this time, a golden kite flew by and perched itself on the nock of Emperor Jinmu's bow, and Nagasunehiko's army was blinded and could not fight.
Nagasunehiko addressed his question to Emperor Jinmu, "Long ago, a child of Amatsu kami (god of heaven) descended, riding on Ame no iwafune (rock boat of heaven). His name was Kushitama Nigihayahi no Mikoto. He married my younger sister, Mikashigiyahime, and a child named Umashimade was born. Therefore, I serve Nigihayahi no Mikoto as my lord. How could there be 2 children of God. How can you try to steal other people's land when you call yourself Amatsu kami's son?"
The Emperor showed Ame no haha ya (the heavenly feathered arrows) and Kachiyuki (Japanese quiver) as his proof of being Amatsu kami's son, and even though Nagasunehiko was awed, he did not change his views. Therefore, he was killed by Nigihayahi no Mikoto, who realized that it was impossible to mediate between the Emperor and Nagasunehiko.
It is said that he was killed by the hands of Nigihayahi no Mikoto, and alternatively, it is also said that he eventually died after his failure at his homeland, but there are theories that imply that in actuality, he advanced north with the support of the Wani clan (Watatsumi family), who was his sibling clan, and he settled in Hirosaki, Aomori Prefecture, with Abihiko, who was a powerful regional ruler in the Kinai region at that time. There is also lore regarding the potential site of his death that hints at the possibility of his involvement in the eastern expedition because he performed a Shinto ritual prior to the eastern expedition in which an arrow was aimed toward the sun to solve political instability and there is also a theory passed down by Yaoi clan, who claim to be his descendants, that says he committed suicide.
There is also a theory that says that he was from a local ruling clan that had power in the area around what was formerly Torikai-go, Soejimo-gun (present-day northern Ikoma City, area around Tomio Station, Nara City), or in the area near Sakurai City. In Kiki (the Kojiki and Nihonshoki), Nagasune is said to be the name of a large village.
He made his younger sister, Tomiyahime, also known as Mikashigiyahime, the wife of Nigihayahi no Mikoto, who rode a Amano iwafune(boat) and descended down on a mountain in Ikaruga called Mt. Shiraniwa, and Nagasunehiko began to serve him.
It is said that his descendant was Tominoichii who defeated MONONOBE no Moriya with Prince Shotoku. It is said that the Oda family (which later turned out Nobunaga ODA) of Yamagata, and the Date family of Sendai, who were both busho (Japanese military commanders) during the Middle Ages and the Period of Warring Sates, were Nagasunehiko's descendants.