Takashiro Giou is a well-respected member of the Giou Clan. He has lived for a thousand years, possessing all knowledge of what has occurred for the past millennium. He is also the adopted older brother of Yuki Giou.
He is obsessed with putting an end to the thousand year war, to the point where he has made alterations to his own body. He puts on a ruthless and cruel disposition when he faces Wakamiya Kanata/Reiga Giou but as Yuki has noticed, is also suffering a lot within. He is shown to genuinely care for Yuki, even though his initial thoughts was to make use of him as a tool to finish up the war. After meeting Yuki, he seemed to have started to feel human emotions once more.
A thousand years ago, he was known to be one of the Four Saints of the famed Giou Clan. He was very close friends to both Reiga and Yomi.
He befriended Reiga despite everyone else shunning away from him due to his partial duras parentage. However that friendship ended when he returned after a mission, to find a sea of flames which was once the village as well as Reiga coated in blood and Yomi dead.
It is hinted that Takashiro and Reiga had romantic feelings for Yomi.
He is a Necromancer who possess the Key of Solomon.
Also able to recover on his own without the help of Yuki (due to the alterations made to his body), as shown when he protected Yuki from being stabbed by several Ice spikes.
He is also powerful enough to force the wheel of rebirth to all those who have fallen from the war.