An inu-youkai
In just words: cunning, graceful & selfish. He prides himself on so-called honesty which holds truth to an extent. Masterfully, he only lets on or does not as much as he deems necessary and has crafted the art of telling the truth in words that very well might make one think otherwise. Literally, Daijiro has a way with words.
A double-bladed sword
Daijiro's father was Inu no Hideaki, also commonly known 'wisdom of the dogs'. Inu no Hideaki was the lesser known and younger twin brother of Inu no Taisho. They were both youkai and while Inu no Taisho went on to father two sons by two different women, Inu no Hideaki fathered twins Daitaro and Daijiro.
Since Daitaro was the elder of the two, Daijiro became jealous. Wanting the prestigious title of Lord of the Eastern Lands for himself, Daijiro killed his brother. He had not intended for his father to have found this out but it so occurred so he deemed it necessary to be rid of his father as well. That in mind, he so arranged things so that Inu no Hideaki was sent into a battle he could never have won. And he did not and perished.
Since then, Daijiro has ruled the eastern parts of Japan, not knowing who controlled the opposite. When he found it was his inuyoukai aunt, who mothered the older of Inu no Taisho's sons, he sought out his cousin to question him. Upon finding he wanted little to do with aristocracy, Daijiro sought to end his aunt's life to control and lord both the Eastern and Western Lands. It was then that the heir to the East finally stepped in.
More recently, word spread of the feud between the East and West and a certain wind witch, now freed after her master's death, sought out Daijiro to aid in his objective to kill his cousin, one she once loved but now scorns after finding her infatuation was only one-sided.