When Hayane saw what happened, she immediately shouted to the 10-year old- girl wearing a red cheongsam-style shirt, "Hey, who are you, kid, and how dare you to kick the boss at his party today." As she said this as she didn't like what the girl who came out of nowhere.
But the 10-year-old girl didn't answer and then, without saying anything, dashed towards Hayane while aiming to punch her gut using her own fists, which was surrounded by metal gauntlets in the knuckles.
But before she can hit Hayane, Reborn, who was observing the fight earlier. Now jumped in and blocked the 10-year-old girl's kick towards Hayane. The reason that although Reborn already sensed the presence of the 10-year-old girl's and knew that she was watching them from more than 50 meters away using some Binoculars.
The reason Reborn was able to sense someone from that far away was due to his years of experience as a hitman, and being involved with the other factions in the world let Reborn pick up a few tricks through the years, which gave him such a high perception.
Reborn, although knowing that someone was observing them, did not do any action before because he thought that even since he knew Tsuna, every time he tries to pull a mischievous prank on Tsuna, Tsuna somehow manages to prevent or escape Reborn's pranks which, although most serious at times Reborn was a bit irritated at this.
Seeing the chance to make Tsuna suffer even a little since he wants Tsuna to get pranked even a little made him actually a bit excited. But seeing the girl was actually aiming to take the life of one of Tsuna's guardians genuinely. Hence, he blocked the hit even if he knew that Hayane could block the fist no problem anyway.
Reborn also knew that Tsuna had a self-healing factor, which was better than most humans and had a healing ability. Hence, he knew that Tsuna wouldn't die in such a hit from a 10-year-old girl who seems to be a newbie assassin. Still, since he saw everyone looking at the Unconscious Tsuna, he was about to shot Tsuna with a special dying will bullet, which was known as healing bullet since he is technically still his tutor and had the job to teach Tsuna how to become the Vongola Tenth and become a proper Vongola Boss in the Future.
Reborn saw Tsuna quickly waking up and looked that he was unharmed, which Reborn expected although a bit doubtful as he rarely sees Tsuna use his healing factor aside from in some spars and using his healing ability to his friends after the spars and training the gang does, which was ordered by Reborn to them.
Then Reborn said to the kicked who was knocked back when he blocked her fist attack towards Hayane, "Hey kid, don't you see that everyone here is a capable combatant and let alone me, the number 1 hitman in the world is staying you're probably an amateur hitman aren't you."
When the ten-year old-girl heard this, she looked like she became flustered as she said to the gang in broken English and a bit terrified voice saying, "I'm sorry I didn't mean to do that. I came here from my master's recommendation when he told me an associate of my master stayed in this house. I thought I'd like to test the students of the associate of my master since I had never sparred with anyone aside from master. And if you mean my killing intent, I release it accidentally when fighting, and I can't control it, yet I'm sorry if you were alarmed by that."
"By the way, my name is I-pin from the Jiang sect from China and disciple of Master Fon." As she clasped her hand and bowed to everyone in the room. When Reborn heard the name Fon, he thought, 'So this was your disciple, huh Fon didn't think you'd actually accept a disciple since when you told me back then that you found no one was worthy of becoming your disciple, so what did you see in this girl. interesting.'
But on the other hand, when Kyou heard the name Fon, she thought, 'Wait could it be my Uncle Fon, No it can't be. I heard that Uncle Fon had disappeared a few years ago; however, I did hear that Uncle Fon was the one who founded the Jiang sect a few years ago, and now Dad's the one' who currently maintains the sect right. But it might just be someone from the sect who has the same name as Uncle Fon this girl is talking about."
Then as Kyou just thought of this I-pin when she finally looked at the gang after bowing when she saw Kyou, she said: "Woah, why is there a female looking master here?!" When everyone heard this, they all immediately took a look at where I-pin pointed in and saw Kyou there.
In a bit of a cold voice, Kyou then said, "Hey, I-pin right, are you sure that I look like a female version of your master." When I-pin, who was fawning over Kyou, a bit shuttered when she heard Kyou's cold voice, and then she just nodded while looking a bit scared.
Then Tsuna, who had already recovered a few minutes ago, patted I-pin's head as he said, "Hey, don't be scared of Kyou-chan here. Although she mostly cold most of the time, she didn't mean anything bad this time. And by that way hit earlier don't hit me again, ok. Even I, who mostly like kids, am gonna be mad if I just get hit from behind and hit the wall."
As Tsuna said, this with an originally kind look to a very intimidating one in the last sentence, which caused I-pin to nod quickly as she thought that everyone in this house was scary. But when she didn't expect it, Kyoko, who saw what was happening to the girl, brought her closer to her as she scolded Reborn, Kyou, and Tsuna, saying:" Hey you three stop caring this girl although she did kick Tsuna-Kun earlier to the wall which was not nice, she looks terrified now due to the three of you showing off your aura's ok not everyone is used to the three of you being cold."
After these events, I-pin when she calmed down, and Tsuna apologized to Kyoko while Reborn didn't bother to say anything as he ignored Kyoko's comment while Kyou didn't reply. And Everyone just allowed I-pin to stay in Tsuna's house for now since Tsuna already forgave her and thought she could join the party.
The gang was about to start the celebration for both Tsuna's and Reborn's birthday while Bianchi and Shammal had just arrived now as Bianchi seemed to have both some ingredients for some food which when everyone heard they tried to forget the taste of the food they ate back then which caused them all to faint. And they only managed to survive that day without poison resistance was because Tsuna, with quick reaction, used his healing skill to everyone and some pills from the system which can cure their stomach poison, which only cost him about 10 system points for 50 pills.
And the reason that Shammal was late because he was actually in the mall earlier and picking up some girls, but he wasn't able to get any, so he only decided to come because he heard that some girls would come to Tsuna and Reborn's shared party, which when he arrived like his usual attitude tried to flirt with Hana but was rejected by every girl who was in the location once again.