KOYO AOBA

Koyo Aoba(青葉紅葉, Aoba Koyo) is a member of the Shimon Famiglia. He previously attended Shimon Middle School, but he and his family transferred to Namimori after an earthquake hit their area. They chose Namimori because it is relatively earthquake free and they are invited to the Vongola Decimo's Inheritance Ceremony. Koyo uses boxing gloves as his weapon, just like Ryohei. Both he and Ryohei also have the same temper, as seen when they quickly get angry and neither of them want to stop the fight. He is sensitive over his contradictory name (Aoba meaning "green leaves," and Koyo meaning "red leaves"). He is firm in his belief that, no matter what his first and last name mean, they are still the same leaves.
Koyo's regular attire seems to consist of his school uniform, and despite his appearance, it belies his brash personality similar to Ryohei. Furthermore, it hides his incredibly fit body, which usually appears slender with his top on. He commonly wears small-framed glasses that are pitch black when looked through but seems like regular glasses to anyone looking at him, and possesses green hair as well as red eyes which seems to be a trait shared amongst the other members of Shimon. His bespectacled appearance gives off the impression that he is a bright individual, however, it only belies his actual intelligence.

Koyo and Ryohei Sasagawa share the same love of boxing. Koyo even has self proclaimed himself as "The Hope of the Boxing World." Despite his love of boxing, his hate for Vongola exceeds and takes precedence over it. In fact, he has stated that he has no boxer pride as his fists are a way to live. This contradicts Ryohei, who has incredible respect for boxing and all of his aspects and fights for is friends. In combat he seems to favor anything but a fair fight, preferring to fight allowing everything that is forbidden in sanctioned boxing including "throwing sand in the eyes, kneeing, and any other form of foul play". Another similarity between the two is that both have some kind of catchphrase. Ryohei refers to many instances as "Extreme" while Koyo tends to end his sentences with "In the End."

He seems to be the most brash member of the transfer students. He easily becomes enraged at even the slightest negative comment towards himself or his family. Koyo showed disapproval of his family being considered beneath Vongola when Gokudera made said comment, which could have escalated if it were not for Adelheid intervening. Still, Koyo seems to have bitter relationships with his family members. One such example is Julie, who he considers lazy when he refuses to partake in his duties. He is not above making fun of Enma, who is the boss of the Family. He seems to be more respectful to women, or at least those he finds appealing, though it could be a perverted trait of his. He blushed, when he saw Adelheid's underwear and called it beautiful, and once commented Tsuna's mother.