Hetaro has blue eyes and medium-length orange hair. He has orange cat ears along with a tail and wears a white robe. Unlike his sister Mimi, he has differently shaped eyebrows and slightly droopy eyes. He is described to be a boy with big round eyes who is easily mentally fatigued.
Unlike his cheerful sister, Hetaro has a more cautious personality, which comes from his experiences of taking care of his sister. As he is a siscon, he generally tends to let his sister do whatever she wants, leading her to grow into her current personality, though because of this he is attentive and is sensitive to changes in mood. Despite this, he is also on good terms with his younger brother Tivey, who listens to what he has to say. Due to Ricardo's habit of heading straight into the battle, he is virtually the commander of the Fang of Iron while in battle.
Sometime in the past, Mimi, Hetaro, and Tivey were abandoned by their parents and were taken in by Ricardo, who they've lived with ever since.
Divine Protection (加護 Kago): Hetaro has the Divine Protection of Trisection (三分の加護 Sanbun no Kago), which he uses in conjunction with his siblings Mimi and Tivey. It enables them to bear each other's physical and emotional burdens and can also be used to split damage between them such as to block death blows. However, as Mimi is the strongest out of the three, her brothers are often stuck with bearing her burdens. In addition, they can launch a destructive interference wave using the Divine Protection and the other siblings, though Mimi is limited to five times and Hetaro and Tivey are limited to two times, so the maximum usage per day is four times.
Resonance Wave: The triplets unleashes a burst of violent destructive mana from their mouths together. Only two of the three of them can do it at a time. This ability was learned from Ricardo as he is the originator of that ability.
Water Magic: Hetaro is able to use Water Magic.
- According to the author, Hetaro's birthday is May 5, the same as his brother and sister, Tivey and Mimi.
- He is the wisest of the three siblings according to the Q&A.