This is a original chapter with slight influences from either the manga or the anime.

First uploaded: November 4th 2010
Updated version: January 9th 2011(Beta'd by gracefulsunshine)
Revised: December 11th 2015

Revised edits: Some changes involve changing the name from Kaitou Jyuudaime to Kaitou Yoshi. To any new reader reading this fic, please note this fanfic runs on pure fun. I may come back to rewrite this when I have time.

Written by: Joythea
Summary: By day, Sawada Tsunayoshi is Dame-Tsuna. By night, he is the worldwide famous criminal, Kaitou Yoshi. A hitman baby comes on his doorstep, telling him that he is going to become the Vongola Tenth. How is he going to cope? AU, no pairings. Might follow manga.
Disclaimer: I do not own Katekyo Hitman Reborn and all rights goes to their respective owners!

Please enjoy and review!

Kaitou Vongola Tenth Chapter 1: Double Life

Warehouse District, Tokyo, 11:00PM

The rather short brunet hurriedly ran on the roof top of an ordinary warehouse, carefully not trying to trip. He had daringly stolen the beautiful gem, the Star Pearl, from the Tokyo Museum, and was currently escaping. A clumsy detective, who-by chance-had noticed him, was right behind him. 'If I catch him, I'll be famous!' The detective smirked, glad that God (or some other celestial being) gave him this chance to catch the famous phantom thief. Said phantom thief noticed his intent, but knew that the detective could never catch him. He suddenly stopped at the next warehouse's roof, while the detective slowly prepared his move.

Seeing that everything was to his advantage, the detective pulled a trap. The ropes under the boy's feet automatically tied themselves to his ankle, but he did not resist; instead, he just went with the flow. The detective assumed that the phantom thief had fell and died (he activated the trap with much force), and started to erupt in maniacal laughter.

"Mwahahahahaha! I have captured-" The detective was stopped when the thief actually used the rope to swing his way back up, and knocked the detective unconscious.

The boy carefully landed beside the comatose detective, and started to untie his feet.

"Sorry, I'll be disguising as you for a while." He said, smirking as he started to disguise himself as the detective.

After he changed into the disguise, the brunet then used rope to securely tie the detective, and went to the source of sirens.

"Detective Narukawa!" The detective turned to see a police officer running towards him.

"Yes?"

"Did you see him?" The policeman asked, panting heavily as he tried to regain his breath.

"Oh, I did—he went that way." 'Narukawa' vaguely pointed towards the end of the pier.

"Men! He went over there. Let's go!" The policeman shouted, and the police force horde stampeded towards the end of the pier.

Detective Narukawa smirked, and started to head home when he noticed a female detective hot on his heels.

"You are definitely a fun person to play with, (2)Tantei-san." Narukawa commented, her heels clicking as she walked over to him. "Or rather…(3)Kaitou (4)Yoshi?" she declared.

" So you found out." Kaitou Yoshi said in his usual deep voice, revealing his true identity.

"Give up. The whole police force is here-you can't escape." she demanded, cornering him.

"I wonder about that." The brunet thief smirked, and threw a smoke bomb to the ground.

'Crap, I should have expected this!' She covered herself as she realized that she made a grave error. As the smoke dispersed, the thief had disappeared. The Star Pearl and his disguise lay on the ground in front of her, with a message explaining that the Star Pearl was a replica. She then smiled. 'Well, there goes Kaitou Yoshi for you.'

Namimori Town, Sawada Residence, Tokyo, 3:00AM

The teen slowly crept into his room from outside the house, and noticed how late it was. He started to yawn, and quickly removed the dummy from the mess of bedsheets. Kaitou Yoshi then turned off the television and the console in the room that gave him a perfect alibi. He took off his dark coat and changed into his pajames, hiding the clothes and the pearl in a secret compartment. The brunet turned off the lights and went into bed, lying on his pillow.

He stared at the ceiling, wondering what to do with the pearl, and sighed. Obviously, sending it to the broker would make him suspicious, so he would have to wear another disguise. 'Nowadays, all the police officers are so boring lately. There hasn't been much of a challenge. I should be more careful in the future…yeah… Be the normal Dame-Tsuna again…' He closed his eyes, falling asleep.

Namimori Town, Sawada Residence, 7:00AM

Sunlight shone through the window, casting light shadows in the room. Tsuna snored in his bed and was sleeping in a really comfortable position. Nana noticed that her son had not woken up, and decided to go upstairs to wake him. As she opened the door, she could smell the dirty stench of Tsuna's room.

There it was.

The stink dropped on her as she saw the room's horrible state of entropy.

His clothes are everywhere, and empty cans and plastic packets of potato chips littered the room. It was as if the world's biggest dumpster moved into her son's room. She noticed a test paper on the floor and picked it up. 'He scored a 20/100? It's always as usual…' Nana thought, knowing that her son wasn't going to suddenly give her a full score on a single test.

She walked over to his bed, and attempted to shake him awake.

"Five more minutes…" Tsuna mumbled, and sleepily turned his back on her.

Nana sighed, 'This is as usual as well…' She then brought up the test paper to eye level and read the results aloud.

"Sawada Tsunayoshi-kun received a twenty in math?" Tsuna woke up upon hearing it immediately, and turned to his mother in horror.

"H-hai! Ah, where did you get that? Uwahh!" He soon fell down and his mother took the sheet of paper.

"Are you okay? You keep falling a lot lately." Nana worriedly asked, seeing how these 'accidents' became more and more frequent. "Maybe I should get a home tutor…" She pondered.

"Kaa-san, I'm fine! Just don't get a home tutor!" Tsuna pleaded, not wanting to be kept indoors all week.

"What's with you? You always stay at home, and always laze off and do nothing…" Nana said, worried about his social life.

'No…actually I go out at night to steal things.' the brunet wryly thought. "I don't want a home tutor! What do you want me to do then?" Tsuna was willing to do anything, just to change his mother's mind.

If a home tutor came, he would be trapped at home all day and night. Which led to the possibility of not being able to steal objects, forever! The gist? He did not want his freedom limited. Nana stared at her son, surprised that he had determination in him.

"If you do get a hundred points…I won't call for a home tutor. Is that fine, Tsu-kun?" Nana said, and Tsuna nodded.

'To ace the next test…that's not funny when you had to pretend that you are useless in academics from the beginning.' Tsuna thought, knowing that his cover would soon blow into pieces. He walked down the stairs to eat breakfast, and noticed the television was on.

"Kaitou Yoshi strikes again! Last night, he struck the Tokyo Museum and stole the famous mysterious Star Pearl, but he gave it back. What is this thief thinking? Is he trying to make a fool out of the police or is he just having fun?" The newsperson said.

'I steal just so that I could have fun mind battles with detectives. But then, the press is sure amazing, creating stupid theories.' Tsuna thought upon seeing the broadcast.

"Kaitou Yoshi is amazing!" Nana exclaimed. "If only you could be more like him."

'You are indirectly praising your son…' Tsuna gaped like a dead tuna fish.

Namimori Middle School, Class 1-A, 8:00AM

Tsuna opened the classroom door, and what he saw: his classmates chatting happily. He decided to ignore them and sat at his seat.

"Hey, did you see the news? Kaitou Yoshi is amazing! He stole that pearl, went poof, and left the pearl behind! What a hero!" A girl happily exclaimed, starting to fangirl over the phantom thief.

"Ahh~ I want to meet him in person!" Another girl dreamily said, clasping her hands together.

Being the target of these indirect praises, the boy just merely sighed.

"Hey, did you hear? The White Orchid is in Japan!" The brown haired teen looked up immediately.

"You mean that phantom thief with a 100% success rate?" Another student said excitedly.

Tsuna rolled his eyes at the mention of '100% success rate'. 'It has to be a bluff, or he got lucky. Never had my heists been that smooth.' Not all phantom thieves succeeded at their heists. Some were captured due to their carelessness or some just had the luck. Tsuna then looked to see Sasagawa Kyoko smiling at him. He then looked away, slightly blushing. 'Why is she bothering to come near me?' He thought, with a flustered expression stuck onto his face.

"Good morning, Sawada-kun." Kyoko kindly greeted.

"Good morning." He shortly replied, pointedly refusing to attempt to continue the conversation.

"Kyoko-chan~!" Kyoko flinched at the sound of that voice. "Come back to me-he's not worth your time!" Mochida shouted from the other door of the classroom.

Kyoko walked over, but not before giving a sad glance at Tsuna. Tsuna just didn't care. There were eye bags under his eye, and adding to his stress was the threat of a impending home tutor he never wanted. He sighed, and starting to sleep on his desk when Yamamoto Takeshi poked him. Yamamoto smiled at him, slightly cheering Tsuna's prickly attitude.

"Yo, my failure buddy!" Yamamoto greeted.

"Yamamoto…" Tsuna's voice trailed off, then immediately started to stretch, not wanting to show Yamamoto his bad side.

He faintly smiled when Yamamoto headed for his seat. Once homeroom started, a silver haired delinquent stepped into the classroom, with the girls falling heads over heels with him. His teacher coughed, interrupting the fangirl screams of the girls.

"Everyone, please welcome Gokudera Hayato, a transfer student from Italy. Please treat him well." His teacher said.

"Hai~" All the girls exclaimed.

'Eek, he's kind of scary…' Tsuna is starting to freak out at Gokudera's dressing. He seemed more like a delinquent rather than a normal student, due to all the skulls he had adorned. He did not wear the uniform properly, giving off the vibe of 'I do not give a damn about the school rules.' Gokudera suddenly walked towards him, and glared at him. The delinquent then moved to his seat at the back. Tsuna tensed immediately as class started; Gokudera's murderous eyes were staring at his back-as if he wanted to kill the brunet right here and right now.

"-Tsuna, please read this sentence on page seventeen in English." The teacher called, and everyone slowly started to laugh.

Tsuna stood up, remembering that he Dame-Tsuna, not Phantom Thief Tsuna. 'Just…this…once…' He thought, clenching his fists. If he showed his genius intellect, then everyone would soon know Kaitou Yoshi's real identity.

He then held up the book to his shoulder level, as everyone else in the classroom braced for a ridiculous result.

"(5)Sensei, are you sure he'll be able to read the passage?" Kurokawa Hana questioned her teacher's decision.

She was the class 'brain', and probably was more fluent than him in English. Or so she thought.

"The man quietly waited for his lover at the restaurant." Tsuna spoke in English with a very heavy Japanese accent, hoping that this accent will be considered "No-Good".

Someone dropped their books.

"Dame-Tsuna...spoke…English…" Another dropped his pencilbox.

The next one dropped her bag.

The last few gasped at his English.

"He…what?" Another person fell off the chair.

"No way…Dame-Tsuna just…" A boy planted his head into the desk.

The classmate beside him just ignored the surprising fact.

Someone else just clapped at Tsuna's efforts. "That's the way to do it, failure buddy!" Yamamoto shouted.

"Good one, Sawada-kun!" Kyoko praised Tsuna.

Everyone else just fainted from the shock that Tsuna just spoke English correctly. Even if it was a very heavy accent, he didn't make a single error. 'I think they remembered I said "I am a pencil!" that time…' Tsuna sweat dropped.

"I'm….not going to do that again." Tsuna commented, as a couple of the students still functioning processed the information that Tsuna read English properly kissed the floor-literally speaking, of course.

The Next Day, Namimori Middle School, Class 1-A 10:00AM

Tsuna was already prepared for the test. He did not even study for it at all. In the previous class he was listening attentively, purposely embarrassing himself by giving wrong answers and letting himself be picked on. The short brunet would have loved to show the class his other side, but only once, seeing that the attention focused on him would be worse than being Kaitou Yoshi.

Once the papers were passed out, Tsuna already took his pen and wrote down the answers. 'You got to be serious…' He thought as he wrote the correct answers with fast speed. Science was like '1+1=2' after being a thief and using so many science-based tricks, understanding logic and fighting mind games on the same level as policemen.

Gokudera observed him from the back. 'He's never this smart in tests…is the information outdated?' He thought, suspicious. The next day, his suspicions were confirmed when Tsuna actually got full marks. Gokudera also did get full marks, but was astonished at Tsuna's achievement. Was he that smart in the first place?

Namimori Middle School, Outside Field, 1:30PM

The school bells rung, ending the class. People began to disperse, taking out their lunch boxes or heading to the cafeteria. Tsuna took out his lunch box and started to eat by himself. In a corner of the classroom, girls gathered, gawking at the silver haired transfer student.

"Sawada, exactly what did you do to get your English to be fluent?" A voice surprised him. "It's unlike you to be doing so well at school for once."

"Kurokawa-san..." Tsuna began. "It's just sheer luck." He said in a nonchalant tone.

"Really." She seemed curious, and almost wanted to probe further but chose not to. "Anyway, you should be careful. Mochida's angry that Kyoko's approaching you. I kind of want to tell him off and leave her alone, but you know how he is."

"Thanks for the concern." Suddenly, Mochida barged into the classroom.

"Where is Sawada Tsunayoshi?"

'Speak of the devil.' He thought.

Mochida pushed Tsuna to the wall-the start of Tsuna's 'punishment' for being near Kyoko. It was the talk of the school that Kyoko was trying to be befriend 'No-Good Tsuna', which made Mochida angry; to have a useless student be let into the popular cliques?

He was never going to let that happen. So, Mochida gripped Tsuna's collar tightly, but the said brunet had no fear-related reaction or expression on his face.

"Listen carefully. Sasagawa Kyoko is my girlfriend. You're better off not knowing her, so steer clear of her! If you hang out with her again, you'll get the ultimate punishment!" Mochida threatened, and abruptly let go of his hold on Tsuna's collar.

Tsuna, in defense, decided to reveal the truth.

"I wasn't trying to be friends with her." He said in a monotonous voice.

"So what?" Mochida angrily shouted, spraying spit at Tsuna's face.

'So unhygienic…' Tsuna thought, spiteful of Mochida's spitting.

"She only wanted to help me. If you can't understand that, how can you call yourself her boyfriend? She's not an object." The brunet began.

"You don't have the right to be lecturing me, Sawada!" The kendo captain clenched his fists tightly.

"I heard some rumours. Something about having another girl outside of school?" Tsuna threw another jibe at Mochida, destroying his pride to a greater extent.

"Sawada Tsunayoshi. You will be dead tomorrow." Mochida angrily declared.

"Mochida-senpai, you still need to obey Namimori Middle School rules." He reluctantly let go, and the brunet walked off.

Italy, Sicily, Vongola Mini-Base, 11:00PM

"Damn that Kaitou Yoshi! I know he definitely stole it, yet he goes off scot free!" Some random idiot angrily kicked the crate of boxes.

Reborn silently stared at the situation before him. The Vongola phantom thieves were still angry about that "Kaitou Yoshi", who had made his debut two years ago and now famous worldwide, even within the Mafia. But right now, it wasn't the time to worry about him. He—Reborn—was going to Japan, on behalf of the Vongola Ninth, to teach an unworthy, normal brat to become the Vongola Tenth.

And that kid is Sawada Tsunayoshi.

End of Chapter 1

I humbly thank gracefulsunshine for taking the time to beta this chapter. Hope you liked the edited version.