The story centers on middle school student Tsunayoshi "Tsuna" Sawada, who finds out that he is the heir to the most powerful Mafia family, the Vongola.
Enemies such as the Kokuyo Gang, a group of Mafia criminals, and Varia, an elite team of assassins, prove to be formidable challenges for Tsuna's new "family".
When the story later shifts into an alternate future, nine years and ten months later, in which some of the characters are transported into, they have to adapt to a world where every Vongola member, as well as their allies, is being hunted down by a powerful rival family of that era, the Millefiore.
characters have also appeared in Akira Amano's early versions of the series that were meant for adult readers due to the violence that it contained.
For the most part of the story, Tsuna rejects his position and wants nothing to do with the Mafia, but due to the results of various conflicts involving himself and his friends, his own power matures and he eventually starts embracing his destiny.
Despite his carefree and outgoing personality, Yamamoto initially has no confidence in doing anything other than baseball, even attempting to commit suicide after sustaining major injury to his arm.
[16] Though he becomes a dedicated and valuable member of Tsuna's family, growing to become a fighter who excels at swordsmanship, he still does not understand the full extent of the situation surrounding the Mafia.
Though he speaks in a calm tone, Hibari is an excellent but violent fighter who wields a pair of tonfa as his primary weapons.
Later on in the story, after possessing the body of Kokuyo Gang member Chrome Dokuro, Mukuro takes on a more supportive role for the series' characters, though still prefers not to associate with them.
[29] After being transferred into the future, Chrome's physical condition takes a turn for the worst as several of her internal organs begin to fail.
Under Future Hibari's instructions, she uses the power of her Vongola Ring to sustain her organs via her own illusions, thus avoiding any immediate danger.
They participate in the Representative Battle of the Rainbow after defeating and stealing the watches of Team Skull in order to get their revenge on Checker Face.
[42] She also has a crush on Kyoya Hibari, who bears a striking resemblance to her master Fon, and often activates the Pinzu-Timed Super Explosion after seeing him.
[43] She can be also transformed into her 15-year-old self through Lambo's Ten-Year Bazooka; the 15-year-old "Adult I-Pin" is more fluent in Japanese, and despite the fact that she is one of the most promising young assassins, she works part-time at a ramen shop ten years later in order to earn money for college tuition, though she still retains her fighting skills.
Even though they seem to have a strained relationship, Bianchi has shown great concern for Gokudera if he is injured, fighting, or suffering from stomach aches, which she does not realize are caused by her (except if they do not have eye contact).
Reborn's chameleon Leon created his main weapons, a whip and Enzo,[52] which is a turtle which grows in size and rampages when soaked in water.
When he ranks people, gravity around him becomes distorted, making objects around him float, and images of stars and galaxies appear in his eyes.
[57] In volume nine of the manga, after he has been controlled by Mukuro Rokudo for quite a long amount of time, it was revealed that he lost his power to rank, and follows the guardians around while living at Tsuna's house.
He is both a skilled doctor (albeit one that refuses to treat men) and renowned assassin known as "Trident Shamal", who was even asked to join the Varia.
However, Xanxus, his adopted son, deemed himself more worthy to become the next boss, so he kidnapped and replaced IX with a fake, who sanctioned the traditional Vongola Tournament.
Their Guardians are quite similar as well: Yamamoto, Hibari, Mukuro, Lambo, Gokudera, and Ryohei have already been shown to be very much like their first predecessors in appearance, weapon of choice, and personality.
[67] He secretly watches over the training of Tsuna and his family,[76] and during the tournament, Iemitsu goes to Italy with his subordinates, and finds out that the IX that has been giving orders was a fake.
He possesses the blue, rain attribute flame, and has the ability to go into Dying Will Mode when he consumes special pills made by Iemitsu.
Later on in the story, Enma becomes possessed by Demon Spade because of his anger and hatred, causing his powers to go berserk, but is stopped by Tsuna for good.
[82] His family is the creator of the Sorry Bullet (嘆き弾, Nageki Dan), which, when shot with and revived, will cause a person to grieve about all the terrible things that have happened in their life, making others feel sorry for them.
He is constantly referred to in earlier episodes as a frequent customer of Adult I-Pin's ramen delivery service, but makes his first appearance when Tsuna and company are trying to hide from the Real Six Funeral Wreaths.
He is later revealed to be the true identity of Checker Face (チェッカーフェイス Chekkāfeisū), a man with iron hat who is responsible for inflicting The Curse of The Rainbow on Reborn and the others, making them the Arcobaleno.
For decades, he had selected and tricked seven people in each generation that he considered the strongest through contract job or representative battle and forcefully make them protect the Arcobaleno pacifier, cursing them into babies.
In ComicsVillage.com's Charles Tan's review of volume eight, he notes that the character designs have a "simple, iconic feel to them," and that they can easily shift from being super-deformed to having serious expressions.
Sparrow of IGN further comments on how the characters are further developed rather than being simply used for slapstick comedy, but due to that, the readers can find themselves being concerned for their well-being.