Takeru is the son of a small local lord, but he has good bloodlines from an old family with a noble lineage, even if it is a side line. He is indifferent to the distinctions of status and class and treats everyone in a natural way. This leads to the strong trust of his friends.

He is proud and courageous as a samurai, won't be intimidated by strong opponents, and respects the will and pride of the opponents. On the other hand, he is gentle at best and lenient at worst, which is fatal to a warrior, as he is reluctant to hurt weak opponents or those who beg for their lives. He has little attachment to land or position, and has a strong yearning for the outside world, which (although not unusual in modern times) might make him a rather strange sort of character in a feudal society.

Takeru is characterised by a crimson mane that grows from the top of his head to the nape of his neck. This is a sign of "blood of oni".
By the time children with oni's blood have reached when they are early teenage years, they have acquired a power that surpasses that of warriors of the 2 or 30s who are in their prime. In the case of Takeru's family, the blood of an oni is contained somewhere in the distant ancestors of the paternal family, and extremely rare 'oni children' are born with bright red hair on a part of their body.

There are other such families in this world, but usually oni's children are regarded as an abomination and bring misfortune to the family, so if they are born in a noble or commoner's family, they are often disposed. In the case in the clans of samurai warriors, although the birth of a strong child is valued, the child's body can't withstand the load of the oni's power and it often dies prematurely or is killed at an early age by rival forces, so it is rare for a child to survive to the age of reaching the teenage.

In the case of Takeru, his family was killed at an early age because of his blood. His father's resourcefulness enabled Takeru to survive, and his immediate goal is to avenge his father's death and rebuild his clan.