Mystery of Tsunayoshi Chapter 1: Prologue: Tsunayoshi's Birthday, a katekyo hitman reborn! fanfic

NOTES

1. There is BDSM, underaged sex, and underaged marriage theme in this story.

2. This is defensive, but English is not my primary language.

3. Another version of this story, with slight differences in the couple first chapters and MA (explicit) content is posted in AO3 under the pseudonym Ms Tea Cup. You can check the link to my AO3 account in my profile. Whichever version you read will not spoil the main plot.

4. If you like this story enough, please continue reading until you finished the Important Note under this prologue. It is for the sake of avoiding some (very possible) confusion.

PROLOGUE: TSUNAYOSHI'S BIRTHDAY

Tsuna couldn't understand it either. People told him he is cute – and Papa even made a specific note by saying he is as beautiful as his mother; But having a very mature man whom Tsunayoshi doesn't know that much making a huge move on him on his 15th birthday is just too much. Currently, Tsunayoshi was still standing near his birthday cake; having just blown the candle a minute ago, smile still plastered on his face even though the corner of his lips twitched a bit. Because something else just happened under that same minute he blew the candles.

A man just kissed him; in front of his guests.

There were gasps around, mainly from Uncle G; his Papa's right hand man. After that, it was a myriad of reactions; mostly screams of threats. Some ran forward with weapons; and Tsuna was sure he heard Uncle Daemon's well-known laughter. The last thing he saw was his Papa's calm composure; but he was sure that – contradictory to his expression – Papa was very angry. Shortly after, his vision was blocked by a piece of fabric he realized was a part of Uncle Ugetsu's robe.

"HOW DARE YOU MADE A LEWD MOVE ON DECIMO!" that's Uncle Gokudera. Behind Uncle Ugetsu's arms, Tsuna could hear the fights getting more and more destructive with sounds of broken glasses (tableware?), explosions (Uncle Knucle? Papa?) and clicking guns (Uncle G?). In the middle of it, he felt the chest of the person behind his back vibrated, then came Uncle Ugetsu's calm voice.

"Maa, maa, everyone, lets calm down for a while. Tsunayoshi-kun is still here". The commotion stopped in a flash, "And, Giotto-san, I think it's better to quickly deactivate your zero point breakthrough mode. It's not wise to have it here with Tsunayoshi-kun in the room, is it not?"

Okay, this means something if Papa went that far. Tsuna could feel himself getting nervous. He didn't understand what exactly is going on and why people reacted so badly to it.

"Now I'm going to get Tsunayoshi-kun out of the room for a bit then you gentlemen can resume your discussion." Tsuna could feel Uncle Ugetsu maneuvering his body around then getting Tsuna to walk with him across the room. After they were out and Uncle Ugetsu closed the door, Uncle Ugetsu instantly let him go from his hold and Tsuna could hear the commotion inside start again. He quickly looked at Uncle Ugetsu; eyes big and panicked.

"All is fine, Tsunayoshi," Uncle Ugetsu pat his head, "Would you like to have a walk with me?"

The implied, "Let's get away from here. FAST." Was clear enough that Uncle Ugetsu didn't even wait for Tsuna's response to put a hand behind his small back and push him forward. They started walking across the hallway in silence; passing through a line of expensive paintings on similarly expensive high walls. Tsuna's mind wandered off, making sense of what just happened.

The party should be a private affair with only ten something people coming. The fact it sound so lonely was fair, because Tsuna spent more than half of his life confined in the Vongola Manor and kept as the Vongola's secret, so he didn't have any friends. He never went to school; he learned everything privately under the constant watch of tutors, mentors, and coaches. Sometimes he went somewhere, if not with Papa himself then with one of the guardians; to experience life outside, but even then he had to put on some disguise and have bodyguards with him.

Attending his private dinner party were Papa and his guardians. Not all of the Vongola's Big Ten could make it; the only ones coming were Nono (Grandpa Timoteo), Ottavo (Auntie Daniela), and Secondo (Uncle Ricardo). The Big Ten is the top ten most important figures in the Vongola, and they receive the best treatment, position, protection, and all the good stuff from the family. Grandpa Timoteo, Auntie Daniela, and Uncle Ricardo supposedly came for a private meeting with Papa; therefore they made it to the party. The rest of the big ten had other businesses they have to attend to; but they had sent their regards and presents.

Aside from those people Tsuna considered family, there were also others. Mainly some maids who babysat him, some guards, none of his mentors thankfully; but this year there was another guy who came as Giotto's personal guest. His name is Reborn.

Tsuna never knew Reborn at a personal level. Even so, he makes his regular appearance in Vongola manor every 3-4 months for some business with Papa. They rarely ever made contacts aside from short exchange every time Reborn joined the family dinner, very few small talks every time they met in the hallway or somewhere else, and, most often, answering questions of his Papa's whereabouts (Where is that no good boss?). He is outstandingly handsome, clad in black suit, with a deep voice and piercing stare. Every time Tsuna saw him, the boy gets this mysterious and dangerous feel out of him. Yet at the same time, he could see how attractive the older man is. Everybody around them, Papa's guardians included, treated Reborn with respect if not fear. And everybody, Papa's guardians included, seemed to reckon whatever it is he does for the family.

He is Italian, and Tsuna heard (from Uncle G) that he was born in a prestigious family of the old royalty kind. He also heard from other guardians that Reborn is a genius, the best in whatever he does, and, as expected, dangerous. Even when he felt intimidated toward the guy, he couldn't help but be slightly awestruck in a curious way by his figure. He seemed to be from another level; a whole different planet to Tsuna's existence.

Uncle G warned Tsuna about Reborn every time the man visited; saying that the only reason Vongola could accept the guy into the Manor is because he was Papa's senior and close friend from high school to university. As dangerous as he is, Tsuna couldn't blame him from being accepted wholeheartedly by Papa. Papa is equally a dangerous figure. While known as a huge corporation by most people, Vongola is also a family who controls the politics and most military actions of notable countries from the background. They are many countries' secret, the evil behind the good, the mafia.

Tsuna doesn't know the exact detail of Vongola's deeds, because Papa made sure he was kept in the dark. And Reborn seems to be one of the things they try to keep Tsuna away from. If he is as dangerous as they made out to be, then he must have represent Vongola's underground business. Maybe an assassin? A drug dealer? A spy? Tsuna wasn't sure, but he was confident the man does something for Vongola.

Even so, Uncle G said that Reborn isn't a member of the Vongola. Instead, he is a contractor; because that's what people of his kind do (whatever that means). Though, if he is a mere contractor, why did Papa invite him to family dinner and something as private as Tsuna's birthday? If Tsuna is a secret, shouldn't he keep Tsuna a secret from a mere contractor? Because Papa kept him away from most of his other business partners; so why brought Reborn now?

This made things more complicated in Tsuna's mind. He just couldn't find something that could push Reborn to kiss him. They were practically strangers to each other. Aside from that, the man was a year older than Papa and the perfect example of a fully matured man with lots of experience in hand. While Tsuna was very young; cute at most; and inexperienced. Tsuna was even very sure Reborn disliked him because that intense look he gave Tsuna every time the man visited the manor clearly spoke of challenge and hatred.

"Don't think too much, Tsunayoshi-kun," Uncle Ugetsu's calm voice broke his mind rant. A glass of fresh strawberry punch (from the dinner party) was offered to him by a maid. Tsuna gladly took it, "What Reborn did is out of his own violation".

"Violation?" Tsuna stated confusedly. Uncle Ugetsu's eyebrows were raised, "Do you understand what a kiss mean, Tsunayoshi-kun?"

Tsuna shook his head, "Papa kisses Tsuna all the time".

Uncle Ugetsu was also having a drink from his own glass – that he spurted out right after hearing Tsuna's last statement. "Pardon?" The man coughed, "Giotto-san kissed you?"

"Is that wrong, Uncle Ugetsu?"

"Uh, n-no! No, of course not! ... that Giotto-san... never learned", Uncle Ugetsu grumbled, "Ah, Tsunayosh-kun, where did he kiss you?"

"Mostly on the cheek, forehead, neck too. He kissed Tsuna on the lips twice, but that usually means he is very tired," Tsuna answered truthfully, "But it's different to the kiss before. Tsuna had never kissed others beside Giotto".

Uncle Ugetsu seemed very annoyed somehow. Actually, he was looking for a hint if Giotto molested Tsuna, but the kisses seemed to be innocent. Good; then he didn't have to report Giotto for pedophilia or incestual relationship. "Okay, do you understand what the kiss before meant, Tsunayoshi-kun?"

Tsuna gave it more thought. "No," he pondered again for a short while, "But Uncle G called it lewd. Does that mean Papa is being lewd to Tsuna too?"

Uncle Ugetsu sighed tiredly, "That's a different matter altogether, that father of yours. But back to the case, a kiss is something you share with the one you love," a pat to Tsuna's head, "Especially the ones to the lips, they are especially saved for the one you love. Reborn-san is someone who could share something as special as a kiss with anyone. But you..., we have to learn to appreciate the one we love, Tsunayoshi-kun. What do you think would a person you love feel if you kiss a stranger like how you kiss them?"

Tsunayoshi wondered too. If someone you love shared something the two of you have together with a stranger, wouldn't that feel as if he or she is putting you in the same level as a stranger? That feels depreciating. Uncle Ugetsu seemed to be able to pick up his answer through Tsuna's expression alone that he smiled gently at Tsuna, "It feels bad, right? Then imagine if someone forces a kiss to someone else – for example, if I were to kiss you on the lips right now, how would you feel?"

Tsuna tilted his head, "But I love Uncle Ugetsu, so I won't feel forced".

"Ah," Uncle Ugetsu suddenly blushed a little, "No, a kiss is something you should save with someone you REALLY love," he stopped a while, looking at the confused stare of Tsuna. Of course he didn't know, Tsuna had been isolated from a normal life, "It's not something you share with family members, Tsunayoshi-kun. I meant love as in more than how you love Papa".

"Oh!" That got a reaction from Tsuna, "No!" he screeched, "I want to save it! Uncle isn't acting fair!"

"Of course, Tsunayoshi-kun. I'd want you to save it for someone you love too," Uncle Ugetsu laughed, "Now, do you understand why it isn't good to share it aimlessly? For one, you're not acting fair to the other party, because he or she might has someone they want to save the kiss for. Then, you're also not acting fair to the you one who loves you".

"Is that what Uncle G meant by 'lewd'?" Uncle Ugetsu answered positively, "Then, what about Papa?"

Uncle Ugetsu visibly sweat-dropped, "Well, Giotto-san used to share that aimlessly too. Back when he was still in school, he rebelled against the family by having a lot of lovers. It's unwise to have a lot of lovers Tsuna, because they ended up feeling sad when they know you love another," Uncle Ugetsu took a breath, "He stopped ever since you arrived into his life, right after he finished school. I guess, some habits still stick around, and that's why he kisses you".

Tsunayoshi nodded understandingly. He heard that Papa used to be unhappy before Tsuna came to the manor. But then he realized something, and his expression turned sour, "That doesn't change anything! Papa is acting lewd toward me!" Uncle Ugetsu answered with a nervous laugh.

After some more talking near the gardens, Uncle Ugetsu took Tsuna to his room. When they passed the then-empty family room – where they held Tsuna's birthday party – Tsuna noticed how destructive the fight was. For one, he couldn't even make out the original setting of the room anymore. Oh well, that's what happens in the fight between Vongola Top Ten, Vongola's guardians, and... whatever it was Reborn does. Tsuna couldn't help but blush at the thought of that man, surprisingly. He couldn't explain that reaction himself.

Later on, a servant told him that he is summoned to Primo's office; which meant Papa made the call. He met some guardians on his way there; coming from the direction of Papa's office. Every time he saw each of them, he received a pat on the head and a hug. Auntie Daniela even shed some tears. Tsuna still didn't understand what's going on.

For one, Tsuna didn't understand their reactions. Shouldn't Tsuna be the one angry here? But why did they react so violently? Are they... possibly Reborn's lovers? Well, if what was told by Uncle Ugetsu true, then they must have reacted so strongly because Reborn shared their kiss with Tsuna, right? But then why would they attack (uh, kill?) Reborn if they loved him? Or is it natural to feel so angry that you'll forget that love?

And the other reason of his confusion is the fact that Reborn willingly kissed him. He remembered how the man walked so calmly to him while he received his congratulations after blowing the candles. At first, Tsuna thought he was going to say something (he doubted it would be a hug because they weren't that close), but then the kiss just came. Tsuna remembered feeling his eyes widening along with the kiss, and Reborn held his gaze with that intense stare; the stare he always sent Tsuna every time their eyes met.

Uncle Ugetsu hadn't explained to him why a person would kiss a stranger aimlessly. Is it really that aimless? Why him? Is it because Tsuna was the only one in the room he hadn't kissed? Then why that particular time and place? Ohhh, so many questions!

And wait, if he was Papa's lover, could he be trying to get some revenge by kissing him because Papa kissed Tsuna?

Tsuna could feel his head pounding. His ever charming intuition, a legacy from his Vongola bloodline, was telling him something is wrong, but his lack of social expertise led him to more confusion. Yet, he understood that this was serious; and things could get ugly.

He finally arrived in front of Papa's office door. Before he knocked, the door was opened from the inside and he was greeted by Uncle Ricardo's tired face. "Tsunayoshi!" The man exclaimed; surprised. The Ottavo looked behind and came Papa's voice, "The sooner the better".

Uncle Ricardo sighed tiredly, "I see", he affectionately rubbed Tsuna's head, "Have you rested before coming here?"

"No, I can't sleep without knowing everyone's condition," Tsuna answered. Uncle Ricardo smiled, but he also seemed... sad. Before Tsuna could say anything, Grandpa Timoteo approached them from behind Uncle Ricardo.

"Come on, let's get going. The sooner we left, the sooner Tsunayoshi and Giotto can have their talk," the old man said meaningfully, "And of course the sooner they can get some rest", he smiled to Tsunayoshi; eyes warm. His wrinkled hand reached for Tsuna's shoulder and with a deep voice, Grandpa Timoteo said, "Just knows that whatever happens, we are family and we are always on your side".

Tsuna wanted to ask, "What do you mean?" But before he could make out the words, Uncle Ricardo and Grandpa Timoteo left the office. Grandpa's words had failed to calm Tsuna's nerve. In fact, it was making the opposite effect.

"Tsuna," that's Papa, "Come here".

Tsuna quickly averted his attention to Giotto's voice and followed the order. Something was going on; he could feel it. Papa could be a cold and strict leader, but he always acted affectionately toward Tsuna. He rarely ever called him Tsuna; he usually called him Tsu; or Tsu-chan if he was being playful. The way Giotto acted around Tsuna was so different to how Tsuna knew him from the mouth of of others that Tsuna almost doubted if Giotto was truly a mafia boss.

But that was another story.

This time, Giotto the leader of Vongola was addressing him as Tsuna. Not Tsu. Not Tsu-chan.

He stepped into the room, closing the heavy rich wooden door behind him.

The familiar sleek office greeted Tsuna in silence. This room shows just how powerful Vongola really is. It's huge, complete with shiny wooden flooring, soft exotic carpets, fully soundproofed wooden walls, sleek wooden furniture, and expensive leather seating. The office table Papa used to work on was located on the farthest end of the room on Tsuna's left. On the right was the sitting area, with five leather couches varying from single to five person sizes and a round wooden coffee table. Near it was the huge fireplace, with a 70 inch flat screen on top of it and built in audio system around it. A bit further than the fireplace was a minibar with artistic mirror on the wall behind it. The lighting was very rich, with a chandelier on top of the seating areas, to ensure you won't even notice the time while you spend your time working inside.

Papa didn't sit on his usual chair behind his desk. Instead, he sat on the single chair on the sitting area, leaning to the side as if very tired. Tsuna approached him and took a seat on the single chair right beside Giotto's. The coffee table was very messy with a lot of dirty crystal glasses, ceramic cups half filled with coffee and a lot of cigarette butts as if they were telling a story of some serious meeting that had just taken place. Then Tsuna noticed that there was another guy in the room. Reborn was leaning on Papa's office table, a drink in hand, and his eyes straight on Tsuna's. Tsuna quickly looked away; nervous and intimidated.

Papa was rubbing his forehead; eyes scrunched shut as if he was thinking hard. "Reborn, I can't concentrate with you here. Could you please be respectable enough to give us some privacy so that we can talk peacefully?" He said sarcastically.

Reborn snorted, "Like you have a say in that after what we've decided".

Tsuna couldn't help but feel a bit offended for his father. Reborn sure had enough nerve to say that to Papa considering this is Papa's office and he is the Vongola Primo. Giotto cursed softly before he leaned toward Tsuna with a strong willed look, "Tsuna, you see...," he hesitated, then quickly adjusted his seat so that he directly sit in front of Tsuna with their knees touching. The Primo leaned closer and Tsuna copied his gesture so that their forehead almost meet.

"Firstly," Giotto started again, "I'm sorry that we had to ruin your birthday".

"Oh," was this what it was all about? Tsuna could feel some of his nerve melting away, "That's fine, everybody has come to visit days before and it has been very lively at home. I've had enough attention the last few days anyway, so... I'm happy. It still is the best week so far," he finished with his signature smile.

Then there was a loud clang from the other side of the room. Tsuna glanced to his side to realized the sound came from Reborn. The man was getting another drink from the mini bar very noisily. When he turned around; he looked very pissed. Tsuna returned his gaze to his father to find how bad his frown got. The anxiety instantly made a u-turn right back to Tsuna. "Tsu, you see, that's not what we're going to talk about".

Tsuna frowned back, "Is this about the kiss?" Giotto became stiff when the kiss was mentioned, "I'm sorry, I don't know you're his lover!"

"Pardon?" That's Reborn.

"What? ... No. No! You got it wrong. You..., how did you...? Where did you get that idea?" Giotto looked at his son incredulously. When the boy mentioned Uncle Ugetsu, the Primo shut him up and said, "Look, whatever it is Ugetsu told you, he must be trying to explain it indirectly for you to the point it caused a misunderstanding. Point is, I have never and never will be interested in that guy," explained the Primo sternly. Reborn snorted. This revelation opened a lot more mystery that Tsuna's intuition screamed 'danger' for.

"There is no easy way to say this. Tsu, the truth is..."

Tbc.

IMPORTANT NOTE

This story is of a mystery genre in which you will have to face many questions before you discover the real story behind what was going on. From here on, you won't be directly shown what happened after Tsuna talked to his father.

My readers, if you decided to stay with me in this story, please continue reading this note.

You will face two arcs; Renato Sinclair's Arc and Tsunayoshi's Arc.

Renato Sinclair's Arc:

- Chapter title will start with Renato Sinclair's

- Will contain different pov's (mostly from Reborn's acquaintances) regarding Reborn and Tsuna's relationship

- This arc's setting is 6 months away from the prologue

- This arc will offer you a huge puzzle surrounding Reborn and Tsuna's relationship, which means it will contains most of the mystery.

- The goal of this arc is to question rather than answer

Tsunayoshi's Arc:

- Chapter title will start with Tsunayoshi's

- Will contain Tsuna's side to the story

- Takes place directly from the prologue until the end of the story

- Will give you the missing chunks of puzzle pieces from Renato Sinclair's Arc. It will be more straightforward and more of a romance.

- The goal of this arc is to answer, and will focus more on Reborn and Tsuna's relationship progression

The reading order of this story is according to what is listed in or as listed below:

Prologue: Tsunayoshi's Birthday

(Renato Sinclair's arc) Renato Sinclair's Track

(Renato Sinclair's arc) Renato Sinclair's Drty Secret

(Renato Sinclair's arc) Renato Sinclair's Masterpiece

(Renato Sinclair's arc) Renato Sinclair's War

(Renato Sinclair's arc) Renato Sinclair's Last Lie

Interlude: Ms. Tea Cup's Challenge Letter

(Tsunayoshi's Arc) Tsunayoshi's Two Cents on First Times

(Tsunayoshi's Arc) Tsunayoshi's Massage and a Drink

(Tsunayoshi's Arc) Tsunayoshi's First Colar (title might change)

(Tsunayoshi's Arc) Tsunayoshi's War (title might change)

(Tsunayoshi's Arc) Tsunayoshi's Piece of Truth (title might change)

Epilogue: Renato Sinclair's Birthday

In chronological order though, the chapters go by: