A middle school boy who dies at the beginning of the series (in the manga he was hit by a van that went out of control after ricocheting off Flandre, whereas in the anime he was hit by a falling iron I-beam after pushing Hime out of the way). He finds himself in Hime's service as he is bound to her because her blood (flame, in the anime) revived him. Though young and not very strong, Hiro manages to assist Hime (mostly by being a human shield) through his "half-immortality" that was given to him after his resurrection. At first, he is rather involuntarily involved in the battles but as he learns more about Hime, he is willing to protect her. His body changes in the manga when Hime's life is in danger (left out in the anime).
In the anime episode 24, Hiro realizes he has developed feelings for Hime and tries to kiss her, but she smacks him in the face, not because she didn't want him to kiss her (this is uncertain), but because the gang was watching them, a theory made from what Reiri said in that moment: "You're too slow, Hiro."
Weapons used: Grass Cutter, Axe, Broomstick, Candle Stick, Metal Pole
