Tsunayoshi 'Tsuna' Sawada

Tsuna is the main character of Katekyo Hitman Reborn.
He's the Vongola Boss and the Guardian of Sky.
Although, he appears to be the wimpiest and most coward, he is the heart and key to the Vongola Family as its Boss.
He uses the "X-Gloves" and his "Dying Will Flame" to fight.

Reborn

Reborn is Tsuna's home tutor, teaching him in the ways of mafia.
Reborn is tough and treats Tsuna harshly.
However, he means well in hopes of having Tsuna grow into a fine young man as well as a mafia boss.

Hayato Gokudera

Gokudera is Tsuna's right hand-man as well as the Guardian of Storm.
He is the most loyal to Tsuna.
He has has a one-sided rivalry with Yamamoto.
Everytime, he sees his sister, he gets sick.
Gokudera fights with dynamite and later, an arm cannon that are fueled by his dynamite.

Takeshi Yamamoto

Yamamoto is the Guardian of Rain and one of Tsuna's closest friends.
Tsuna considers him one of the few 'normal' friends he has.
Unlikely, it seems, he and Gokudera are best friends.
Considered a natural-born hitman.
He fights using a katana.

Ryohei Sasagawa

Yamamoto is the Guardian of Sun and Kyoko's older brother.
Tsuna calls him 'big brother'.
He is considered the most energetic Guardian.
He fights using his hands; particularly in boxing.

Kyoya Hibari

Hibari is the Guardian of Cloud and leader of the Discipline Committee .
It seems like Hibari doesn't like anybody, but he does respect MOST of the members of Vongola.
His catch phrase is 'i'll bite you to death'.
Hibari fights using tonfas.

Chrome Dokuro

Chrome is the Guardian of Mist and shares her body with Mukuro..
She seems like to Tsuna the most (Besides Mukuro) due to Tsuna caring about her greatly.
She lives with Ken and Chikusa who treat her harshly, but they like her, kinda.
Chrome fights using her trident or by summoning illusions.

Lambo

Lambo is the Guardian of Lightning and is best friends with I-Pin.
Lambo is very cocky in his abilities and enjoys making fun of people.
He currently lives with Tsuna, spending most of his time playing with I-Pin.
Lambo fights with hand-grenades, or when he cries, he jumps into the 10-year bazooka and takes on the form of Adult Lambo who uses lightning itself to fight.