Yuusuke has brown eyes and short black hair, which he usually keeps slightly-spiked with hair gel. He has around half a dozen small bangs which he doesn't keep spiked. Instead of wearing the school-issued blue uniform of Sarayashiki Junior High, he wears a identically-designed green uniform. He does this in direct rebellion of the school's strict dress code. Throughout the series, Yuusuke's clothing changes, but he usually wears some type of fighter's garb. Yuusuke looks rather-skinny, a stark contrast to his unusual strength. At the beginning of the series, he was also quite short as seen when Keiko points out he was shorter than she was. Having no father and with his mother always off somewhere else, getting drunk or partying, Yuusuke has grown up in a very neglectful environment. He's short tempered, impulsive, and likes to intimidate those who are afraid of him. One of his most notable traits is his desire to fight, which becomes more noticeable as the series progresses. Yuusuke has been noted on many occasions to being rather unintelligent and, at times, just plain stupid. Yuusuke's desire to fight is more out of enjoyment of a good brawl, and surprisingly Yuusuke doesn't like killing if he can avoid it. Even though Yuusuke is feared by most students; and severely disliked by almost all of the teachers, he is generally misunderstood. Keiko Yukimura is one of the very few who knows Yuusuke is actually very kind, and she sympathizes with his problems in life. Yuusuke and Keiko quickly develop strong feelings for each other; and he is fiercely protective of her, almost always worrying about her well-being. Yuusuke initially didn't like Kuwabara, but as the series progresses, the two develop a mutual bond and respect for each other, with Kuwabara being the only person who truly understands him. Yuusuke and Hiei have a serious rivalry and, at times, Yuusuke seems almost intimidated by Hiei's remarkable skills. Yet, each of them has respect for the other, and will put their lives on the line to help one another. Yuusuke is very close to Kurama and has a great amount of confidence in him. Yuusuke respects Kurama's wisdom, sometimes looking to him for leadership advice when he's not sure what to do.

Gokudera was born in Italy and is 3/4 Italian and 1/4 (mother) Japanese. His blood type is B, is 168 cm tall, weighs 54kg and his hair is silver. His future dream is to become the Tsuna's right-hand man. He has an ability to play the piano. He dislikes people that are older than him, Bianchi and Lambo. Gokudera is also a chain smoker, but they remove this in the anime adaptation. At school, Hayato is adored by many of the female classmates who view him as the "rebellious badboy." During Valentine's Day, a large group of females constantly followed him around trying to give him chocolate, although Hayato seemed to be more annoyed than flattered by this. Despite his image of a rebel, Hayato excels in his schoolwork and aces all his tests, much to the surprise of Tsuna. This is probably due to his rich upbringing, suggesting that he probably had a multitude of private tutors when he was young. He idolizes Tsuna greatly and considers himself to be Tsuna's right-hand man. Due to a traumatic childhood experience, every time he sees the face of his older sister, Bianchi, he becomes sick, sometimes even falling unconscious. Oddly enough, he is immune to his sister when she happens to be wearing something that covers part of her face (i.e. glasses or goggles).