Reborn's doctor costume. It is first seen during the Daily Life Arc when Reborn is trying to wake Tsuna for school. After the events of Tsuna confessing to Kyoko and fighting Mochida, he ends up having to shock Tsuna, which, as claimed by himself, is the "special Vongola way" of waking a person. Reborn wears a head mirror on his head and wears a pair of metal plates for letting electricity through.
Reborn's construction man costume. It was first seen during the Daily Life Arc when Reborn was tutoring Tsuna on mathematics. Reborn would detonate a bomb on Tsuna whenever the latter got an answer wrong. Lambo makes his debut at this tutoring time as well.
Reborn's pajamas are first seen when Tsuna and Yamamoto were having test problems and the Family (Gokudera, Kyoko, Bianchi, and Haru) were trying to help them. Reborn sleeps at this time wearing this outfit, only waking to say a few words; however, he later wakes up to give the correct answer, prompting Haru's father to identify Reborn as Doctor Borin, a prodigious infant mathematician. Also, every night, Reborn is seen with this pajamas to sleep in.
Reborn's chestnut suit was first seen when Gokudera claims that it was boring in the house. As a result, Reborn comes in this suit, the suit's name being a pun on words in Japanese. "Bikkuri" means "surprising", and "big kuri" means "big chestnut". Reborn uses this costume to spy on people who use trains for long distance commuting. People are scared of the spikes, so nobody bothers him. The costume was actually made by Bianchi when she was in elementary school for home economics class. The one who touches the spikes would go to heaven in 30 seconds, as claimed by Reborn himself. Reborn appeared as this costume again when Tsuna, Dino, Yamamoto and Gokudera went to Death Mountain.
Reborn's "Master PaoPao" costume. A Thai boxing elder, PaoPao; although the one wearing is it actually Reborn in disguise. Reborn appeared as Master PaoPao again on top of a hippo named Saizou when Tsuna and Kyoko were on their first date.
Reborn's exorcist Costume, a costume worn by Reborn when the nurse was getting sick of Tsuna's disruptions in the hospital. The nurse put Tsuna in a small lab room full of insects and animals in jars; Reborn comes in with his exorcist costume and with the help of I-Pin, they come to exorcise Tsuna's room of the "evil spirit" that was causing all of his injuries.
Reborn's astronaut costume, worn by Reborn when Fuuta was ranking Haru's three most attractive features. It was seen again during the 291st chapter's colored cover page of Akira Amano's Katekyō Hitman Reborn!
Reborn's detective costume, worn by Reborn while he was conversing with Dino about the Kokuyo Junior High Gang. Reborn wore this costume again during the Varia Arc when Reborn recommended Tsuna to researching for Lambo because he didn't come home for a long time.
Reborn's Vongolavsky costume, worn by Reborn to secretly assign Tsuna, Gokudera, Yamamoto and Kyoko in the same class; the school board also thinks that "Vongolavsky" is a special classroom assigner. Reborn used this costume to run all over Namimori Middle until Kyoko wins by catching him on top of the roof. With that, they get to be in the same class.
Reborn's graduate costume. it was first seen during the Daily Life Arc. When Tsuna's group had trouble on problem #7, Haru call his dad for help. When he can't solve the problem, Reborn said that there is a answer to that problem. While Reborn was talking, Haru's Father noticed Reborn's sideburns, he recognized Reborn as Professor Borin, a mathematical genius that can solve every single problem previously considered impossible to solve. It was shown again when Borin was talking with the Principal and one of the staff members, right after Kyoko took the assigning clipboard from Reborn so they could assign themselves to the class that they wanted to be placed in.
Reborn's swimwear, worn by Reborn when Tsuna's family and friends were trying to teach him how to swim. Reborn wore this swimsuit again when Reborn surrounded Tsuna, Kyoko, and Haru around things with that are hot like a tea on a stove, etc. and Reborn on the side cooling down in his swimsuit surrounded by cool things like a pool of ice under him and drinking a cold drink.
Reborn's plant costume. It was first seen during the Daily Life Arc when Tsuna and Yamamoto failed their math test and Reborn decided that the extra credit they got from their teacher should be done at Tsuna's house. It was seen again when Squalo fought Basil, Tsuna, Yamamoto and Gokudera for the fake Half Vongola Rings.
Reborn's teacher outfit, worn by Reborn when he took over Tsuna's class during the Open House. He started to teach the class because the teacher is busy taking care of Gokudera because he saw his sister, Bianchi. After inroducing himself, he told the class that they're going to work on their muscles so Reborn wore a gi to best fit the situation.
Reborn's pigeon costume, worn by Reborn during the Varia Arc when Haru was testing Tsuna to see if he's a good or bad person. He was spying on Haru with this costume with Bianchi holding him on her hand.
Reborn's ninja outfit, worn by Reborn during the Varia Arc when popping up on the window when Tsuna was asking Dino about Hibari's fighting condition. Also Leon is the headband. During some episodes, Reborn would be dressed as a ninja to do things secretly like listening in a conversion.
Reborn's girl costume, worn when Reborn was supporting Kyoko and Haru's boycott, the former and the latter initiating the boycott because of being kept in the dark about the fight with the Millefiore Famiglia.
Reborn's chef costume. It was first seen when Haru was by Tsuna's house and saw that Lambo was driving Tsuna crazy, as always. Haru was wondering why Tsuna was acting this way. Reborn and Bianchi showed up behind her and asked if she wanted to eat Italian oden. Reborn appeared as this costume again in Haru Haru's Interview: Dangerous when Bianchi appeared as a special guest.
Reborn's pizza delivery costume. It is first seen during the Daily Life Arc when Reborn wants Tsuna to be in the volleyball match. Reborn did this by poisoning the pizza, thus making the volleyball players unable to play and makes Tsuna a volleyball member.
Reborn's camouflage costume. It was first seen during the Daily Life Arc when Dino was explaining the training that happened when Reborn was his tutor. He wore a camouflage suit when Dino failed at fighting a bear with his whip.
Reborn's haiku reading costume. It was first seen during the Daily Life Arc when Tsuna was sick with the Skullitis disease and it was almost time for Tsuna to die and Reborn was reading a haiku about Tsuna living a short life and ending in the sunset.
Reborn's cupid costume. It was first seen during the Daily Life Arc when Hana was thinking what made Tsuna so passionate to find out who Kyoko gave her chocolates to. Hana thinks cupid shot him with his arrow. And the cupid shown was Reborn.
Reborn's hunter costume. It was first seen during the Daily Life Arc when Reborn, Bianchi, and Lambo were eating the expensive sushi and they ran away because they didn't want to pay the bills. The bill was 70,000 yen. Because Tsuna didn't have that much money, Reborn, in his hunter costume suggested that he should work to pay the money off because Reborn said that a person who doesn't work doesn't deserve to eat. Reborn appeared as this costume when Tsuna was training to learn Zero Point Breakthrough: First Edition for the Varia Ring Battle.
Reborn's catfish costume. It was first seen during the Daily Life Arc when Tsuna gave up confidence on learning how to swim. This costume is instilled with lightning. Reborn used this costume to electrify Tsuna and keep him from giving up.
Reborn's diving suit. It was first seen during the Daily Life Arc when Tsuna and this senior lifeguard was swimming for a race. Tsuna saw a little girl floating away to sea. Tsuna decided to risk his life to save that girl because when he was a kid, he floated away to sea and lifeguards saved him. When he reaches the girl, he sinks. Reborn, in his diving suit shot Tsuna with a Dying Will Bullet and saved the little girl.
Reborn's construction suit. It was first seen during the Varia Arc when Tsuna heard about Gokudera training by himself. He rushes over there and see Gokudera trying to throw dynamites, but can't because he was heavily damaged. Gokudera tries it one more time and fails, but luckily, Iemitsu dug a hole with Reborn to protect him.
Reborn's vase costume. It was first seen during the Varia Arc when Gokudera was done explaining the events that happened so far in the Vongola Ring Battles. Reborn, in this costume, caught Gokudera being nice to Lambo for once.
Reborn's old sensei costume. It was first seen during the end of the Varia battles and the gang were celebrating at Yamamoto's sushi place. When Basil and Lacia are leaving to go back to Italy, Lambo is seen running around. When Reborn was pissed, he attacked Lambo with Leon's version of Violent Snake Fierce Domination. Lambo was crying after, and threw a huge pack of his grenades at Tsuna. Tsuna was seen flying away and ended up hanging on the telephone pole. Reborn was seen with this costume and told Tsuna that he needs more training. After, Tsuna cried for help.
Reborn's eggplant costume. It was first seen during the Inheritance Ceremony Arc when Yamamoto wanted to see how good Kaoru is at baseball. He commented that he was nervous when other people watched him play. But, he was able to play after Reborn and the others wore vegetable costumes made by Haru and cheered for him. When he threw the ball, the ball vanished as Yamamoto caught it. This made Reborn wonder what he was capable of and only furthered his theory that the Simon Famiglia wasn't as weak as they were rumored to be.
Reborn's kimono costume. It was first seen after the battles with the Varia. Reborn, in this kimono, suggested Tsuna to take a "winter test of courage." Reborn wore another kimono during winter test of courage when Reborn was telling Tsuna that he was late and that his partner was waiting.
Reborn's nagging costume. It was first seen during the Daily Life Arc when Tsuna asked if Reborn was supposed to be a naggin mother-in-law and Reborn got mad and started smacking Tsuna with a broom in the butt.
Reborn's maid costume. It was first seen during the Daily Life Arc when Reborn scolded Tsuna for not squeezing the towel hard enough. Tsuna asked how this deals with training and Reborn started hitting rapidly with a towel.