Takumi is the third child of four in the Hoshidan royal family, being the younger brother of Ryoma and Hinoka, the older brother of Sakura, and the second son of Sumeragi and Ikona. In addition, he is the stepson of Mikoto, the stepbrother of Corrin, and the adoptive brother of Azura.

In order to gain recognition for his strength, he has been tirelessly perfecting his practice of martial arts. Although not explicitly stated, Takumi does have some skill with the blade, but when he was humiliatingly crushed by Ryoma during a sparring match many years prior to the events of Fates, he chose to become an archer instead. Takumi is portrayed in a state of moody malcontent and desires recognition for his own talents without being overshadowed by the achievements of his older siblings. This serves as a blessing and a curse; on one hand, it has spurred Takumi to be austere in his efforts to hone his skills, making him a very skilled archer. In his supports with Mozu, he disproves her doubts over his farming capabilities by tirelessly engaging in manual labor on the field. However, he is mentally weak due to his overwhelming inferiority complex, as especially shown by his constant, seething words of hatred under Iago's influence. The conversations he shares with Kiragi exemplify this complex as well: his immediate reaction to witnessing his son's stellar hunting skills at a young age is jealousy at the possibility of him surpassing him and mastering Fujin Yumi.

Despite trying to hide it, Takumi has also a slightly childish mentality, as he often lets Camilla and Orochi's teasing get to him in their supports, and admitting in Hinata's supports that he enjoys watching him trounce others in sparring. He actually wants to go to the beach while trying to deny it, and admitting as much if he's defeated.

Takumi cares immensely for his siblings. He looks up to his elder brother, Ryoma, and demonstrates a strong will to protect Sakura from any harm. He also cares for his elder sister, Hinoka, but behaves particularly harshly towards her when she reciprocates with her own care (such as with wounds from battle). He has light long hair tied in a pony tail and has red eyes.