Hiro Souma

Hiro is intelligent, sarcastic and argumentative. He can identify inconsistencies in another person's words almost immediately and then press them through a barrage of questions until the conversation becomes exhausting.

That sharpness frequently hides insecurity. Hiro is painfully aware that he is younger and physically less capable than many of the people around him, particularly when he wants to protect Kisa.

He gradually becomes more considerate without losing his blunt personality. His family life, growing responsibility and exposure to Tooru's patience force him to recognize that being clever does not excuse cruelty.

As the Sheep of the Zodiac, Hiro transforms into a sheep when the curse is triggered.

He has no specialized combat training emphasized in the story. His principal strengths are intellectual: Hiro is quick-thinking, verbally agile and unusually perceptive for his age.

His small size and youth limit what he can physically do against older members of the family, a fact that contributes to his frustration when people he cares about are harmed.

Hiro initially appears as an antagonist in miniature, stealing Tooru's belongings and attacking her verbally because he resents the affection Kisa gives her. Kisa's disapproval forces him to reconsider that behavior.

His deeper motivation emerges through his relationship with Kisa. After Hiro tells Akito that he loves Kisa, Akito attacks her. Hiro witnesses the assault and subsequently distances himself from Kisa because he believes his confession caused her suffering.

Hiro's home life develops alongside that guilt. The birth of his younger sister Hinata gives him a new protective responsibility, while witnessing further violence within the Souma family makes him increasingly unwilling to remain silent.

Kisa Souma is Hiro's closest friend and romantic interest. He deeply loves Kisa Souma, but fear after Akito's attack causes him to distance himself from her temporarily.

Tooru Honda initially irritates Hiro because Kisa adores her. His attitude toward Tooru Honda gradually softens as he recognizes her sincerity.

Satsuki Souma is Hiro's mother. He loves her but frequently worries about her absent-mindedness and clumsiness.

Hinata Souma is Hiro's younger sister. Her birth brings out a more openly affectionate and responsible side of him.

Akito Souma inspires fear and resentment in Hiro. Hiro carries guilt after witnessing Akito injure Kisa and later becomes burdened by another act of violence he is initially unable to reveal.