Hibari Kyouya♂

Hibari Kyouya is the leader of the Namimori Middle School Disciplinary Committee, prefects who are in fact a group of delinquents that are all loyal to Hibari. Hibari himself is a violent delinquent who uses his status to harass other students. As shown several times in the series, he prefers to be alone and cares little for his subordinates. He loves Namimori more than anything, and will often say "I'll bite you to death," or "kamikorosu," to those that disturb Namimori Middle School. Hibari is very proud of his school and is apparently the only person who even likes their school's anthem, even using it as his ringtone. Reborn piqued Hibari's curiosity in the mafia early on in the series and Hibari considers him a worthy opponent, having a strong urge to fight him.

As stated by others, Hibari is a very scary character with no care for the well-being of others, preferring to do whatever it takes to get what he wants. This often leads to his opponents surprising him, as he doesn't think before attacking. As the head of Namimori Middle's Disciplinary Committee, Hibari uses authority to assault those that get on his nerves, including his own subordinates. He prefers to be alone, and hates crowdings. This leads him to beat anyone who he thinks is crowding around him too much. He has full confidence in his own strength and power, and dislikes working together with anybody due to feeling bound and restrained, making him refuse or not easily take suggestions from others into consideration.

A rare trait about him is his love for small animals, ranging from birds to hedgehogs. He is also fiercely loyal to his school and its rules, going so far as to punish others for breaking them even if they aren't students or at the school. He is shown to dislike being indebted to anyone and strives to pay them back as soon as possible. He cannot stand being restrained and absolutely refuses to allow himself to be controlled.

[Taken from Reborn! Wiki.]