Historically: the son of Kakizaki Kageie. He was sent to Odawara Castle in Sagami when the Kenshin and the Houjou clans struck a peace treaty in an exchange of hostages with Houjou Saburou (Uesugi Kagetora). The fate of Kakizaki Haruie was unknown when his father was accused of treason. There are theories that he either died in 1575 along with his father, or that he was murdered by Uesugi Kagekatsu's faction in 1578 during the Otate no Ran.
In Mirage of Blaze: He was one of Uesugi Kagetora's most loyal followers as well as the leader of his faction in the Otate no Ran, and was killed by Uesugi Kagekatsu's followers. He is now one of the Yasha-shuu under Kagetora's command. Haruie possesses female bodies (the only member of the Yasha-shuu to do so) in search of a lover who died two hundred years ago.
Of the Yasha-shuu, he is the one who excels most at the spiritual sensing ability called reisa.