Mimi's Pov.

School has ended and right now I'm at the park waiting for Tsuna and Reborn-san.Then I felt my phone vibrate,I pick it up and see Shirou-kun's calling me.I accept the call.

"Hello? Shirou-kun?"I said.

"Hi,Mimi-chan.Me and the others are going out. Do you want to join?"Shirou-kun asked me.I sigh.

"I'm sorry,I can't. I have to help Tsuna for his studies...Sorry"I said,I really feel bad right now.

"Oh,it's Ok.I understand. Well...See you at school.Love you Mimi-chan"Shirou-kun said and I smile.

"Love you too,Shirou-kun"I said and ended the call.

"Ciasuu~ Sakurai-san"I heard a voice...and that is Reborn-san's voice.I turn around and see Tsuna with Reborn on his shoulder.

"Now,please explain me all of the things you told me before"I said to him and he nodded.

"You see,Some Mafia's are hunting for Tsuna and as far as I know this is the only place that can make Tsuna safe for a while. I can sense there is not Mafia in this City.So me,Tsuna and his other guardians will be staying in this city for a while"Reborn explained and I nodded.

"Ok...But what about me being a Crystal....Guardian?...I don't even know what that mean..."I said.

"Crystal Guardian...Meaning you have a power of Crystal and can make onlu three swords.But these swords are powerful,so powerful that can make some powerful Mafia down. I tried to train Tsuna for the Crystal powers,but it says that only one person can handle this energy...And that is you"Reborn said as Tsuna look at me.

"M-Me? But how? I'm only a normal girl.."I said.

"That's what you thought. Didn't Miku and Saru told you about their family?"Reborn asked and I shook my head.

"No...They don't like it when I ask about it...So I just shrug it off..."I said.

"Well as you can see Sakurai Miku and Sakurai Saru have been part of the first Vongola family which the heir was Primo (If you don't know the Anime,please watch it. That Anime is soooo coool! And has a great story!).But both of them managed to get a potion that could make them young.Primo helped them to find it,because only your mom and dad can handle the Crystal Power. When I saw you at the first time,I knew it was you....Sakurai Mimi the new Crystal Guardian of the Decimo Vongola."He expalined my eyes widened.

'So...That means....I'm not what I thought to be?...I didn't know my life would be change since I met Reborn and Tsuna....'I thought.

"Will you accept to be Decimo...or Tsuna's new Crystal Guardian?"Reborn asked me.I look at him then Tsuna who look nervous and then Reborn.

"Well...since I got no choice...I guess I will join"I said and Reborn smirk.

"Good choice,but let me remind you.You cannot tell these to no one...even your friends...You don't want them to be involve to this,right?.It'll be dangerous for them"Reborn said and I nodded.

"Good.Now let's go to Tsuna's house and let me introduce to you,the other guardians of Tsuna"Reborn said as the three of us started to walk.

'I can't tell about this to Shirou-kun??...Well I guess it's for the best...I don't want him or my friends or family to be hurt...I don't want them to be in danger....'I thought.

No One's Pov.

Mimi,Tsuna Reborn arrive to a big mansion,Mimi look shock.She didn't expect Tsuna's house would be a mansion!

(This is Tsuna's Mansion...Just pretend ok? Hehe..).

"Wow! I never knew your house would be so big,Tsuna!"Mimi said.

"Hehe..You think so?"Tsuna asked and Mimi nodded.

"Come in"Reborn said as he open the door.

"Wow! It's more beautiful inside!"Mimi said as she look around.

"Judaime! Your back!"The three of them heard a voice.

(Judaime means Tenth in Japanese)

Then they saw a tall boy with gray hair and green-ish eyes.

"Judaime...Who the hell are you?"The boy asked Mimi rudely.

"Gokudera-kun,please be nice to Mimi-chan!"Tsuna said to the boy who only look away angrily. Tsuna turn around and look at Mimi.

"Sorry about that....It's just the way Gokudera-kun speaks to others..."Tsuna said and Mimi nodded.

"It's ok. It's nothing serious"Mimi said and smile.

"He's Hayato Gokudera,he's my Storm Guardian"Tsuna said,then Mimi can't help but to notice it.Something is not right.

"....For some reason...I can feel or sense...some people are in this place maybe five people...other than the four of us..."Mimi said,Tsuna and Gokudera look at her shock.

"W-What????"Mimi asked.

"H-How did you know....That some people mught be here?!"Gokudera asked and Mimi look at him.

"I don't know..I only sense it..."Mimi said and Reborn smirk.

"Impressive....one of your abilities is working.Guess I will not train you with that"Reborn said.

"Abilities?"Mimi asked.

"I'll explain to you later.Now let me introduce you to the other Guardians."Reborn said as the four of them walk in to the living room.

And to Mimi's surprise there are five people in the room.

"Ah! Tsuna-kun!...Who is she?"Said a black hair boy.

"I'm Sakurai Mimi...Please to meet you"Mimi said and the boy smile.

"I'm Yamamoto Takeshi.Tsuna's Rain Guardian"Takeshi said.

"I'm Sasagawa Ryohei!The Sun Guardian!"Ryohei said.

"I'm Dokuro Chrome.Mist Guardian"Chrome said.

"Hibari Kyoya.Cloud Guardian"Kyoya said.

"And I'm Lambo!The Lightning Guardian! Do you have a candy???"Said a little baby who look like a cow?

"Ummm...I do have a lollipop here"Mimi said and pick a lollipop on her bag and give it to Lambo,who gladly took it.

"Yay! Thank you! I already like you!!'Lambo said and hug Mimi who smile to him.

"Now,Lambo let her go"Tsuna said and Lambo did what he said.

"So...Why is she here?"Chrome asked.

"She's Tsuna's new Guardian..Crystal Guardian"Reborn said. Takeshi,Ryohei,Chrome,Kyoya and Lambo's eyes widened.

"W-WHAT?!"They all said...well Kyoya didn't,he only stay quiet but he is shock too.

"Well it's because Her parents are Sakurai Saru and Sakurai Miku...first Crystal Guardians of Primo"Reborn explain.

"B-But...How?"Lambo asked.

"Well....Primo knew that Her parents are now the only people who can handle Crystal Powers....So he and the others helped them to find a potion that could make them live long enough...And now the potion is already expired...But Mimi here has the same powers as her parents"Reborn said and look at Mimi.

"Now....I think we should train you.Don't worry it'll be easy"Reborn said and smirk.

'I have a feeling that it isn't going to be easy....'Mimi thought and sweatdrop.

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Hi Guys! I guess I'm gonna make this one-shot long than I thought! But I hope you still read it!!! Oh! And there's something I need to tell you,This Crossover is gonna be a little bit different than the last time (Atsuya x Oc) and I'm gonna change something on the next Part! And I hope you guys are gonna like it!!

Please leave a vote or a comment for about what you think of this One-shot! Thanks!