Hikaru knew Kakashi would be late and he's not an impatient guy, so he waited patiently for his sensei. Though, that could not be said for the other three.
"Ugh! That sensei of ours better appear now, or else I'll pummel his face!" Sakura screeched like a banshee.
"Hn, that guy better appear, " Sasuke said while brooding. He sat at the far back, away from Hikaru, who's sitting right beside Azumi.
"Hmm, just wait patiently Azumi, just like what Hikaru-kun told you to, " Azumi said to herself to calm her anger down.
As Hikaru sat and listened to his teammates, he suddenly sensed a familiar chakra presence behind the classroom door. It was much larger than others, though it's 1/4 to Azumi's chakra level. He deducted that this must be Kakashi. He then decided to play a little prank for him being late.
Do you guys remember the pyromancy called Iron Flesh? Yeah, he would use that to Kakashi to make his movements much, much slower.
As soon as the door was opened, Hikaru appeared in front of Kakashi with the pyromancy hand in his left hand before touching Kakashi in the chest with it, he then used Iron Flesh to make Kakashi heavier. As soon as his pyomancy hand touched Kakashi, he became encased with iron.
All of this happened in less than a second and when Kakashi finally noticed it, Hikaru was backed on his seat, like nothing ever happened. His pyromancy hand was nowhere to be seen.
"Yo- why do I feel I so heavy?" Kakashi tried to greet them but he noticed that his body has gotten a lot heavier.
"Ah, Kakashi-sensei, you're finally here. Hmm, is something wrong?" Hikaru asked politely but you can see a mischievous glint in his eyes.
When Sasuke, Sakura, and Azumi saw Kakashi, they were beyond shocked. They were extremely baffled because Kakashi is completely encased in iron, even his clothes were not spared.
"S-Sensei, what in the world happened to you?!" Sakura asked, baffled.
"Huh? What are you talki- Oh my god!" He was confused at first but then, suddenly, he noticed his arms were completely encased in iron. He tried looking at his body but only noticed nothing but iron covering his flesh. No, that could not be more inaccurate, his flesh IS the iron.
As he was about to lose his mind, the iron in his flesh suddenly disappeared. And not a few seconds later, all the iron was gone.
Hikaru stood up and walked towards the door. As he passed by Kakashi, he whispered silently behind Kakashi, "Don't be late next time, Kakashi-sensei. Even though I'm a patient guy, I still have limits." With that, and as soon as he walked out of the door, Hikaru suddenly disappeared. He is heading towads the rooftop, where he knew that that was the place where the original team 7 gathered.
Kakashi turned around after he heard Hikaru whisper, only for him to find nothing but air. "What was that?" He muttered.
He decided to ignore it for now and immediately get on with his cute little students. He turned back to the genin he's going to teach, (If they pass his test), and eyes smiled to them before saying, "My first impression of you guys... is that I'm having a very bad feeling. Anyway, go to the academy rooftop. That's where we'll be having our first meeting."
As soon as he finished saying that, he used shunshin to disappear and go to the rooftop without any trouble.
'Hn, is that really going to be my teacher? He looks dumb, ' Sasuke thought with disdain towards Kakashi.
'Hmph, I don't care about who's going to be my teacher. As long as I'm with Sasuke-kun, I don't care what happens, ' Sakura thought as she stood up to walk towards the door, along with the other two.
'What was that? Why did our sensei suddenly became covered in iron?' Only Azumi thinks about that, unlike the other two.
(At The Rooftop)
When Kakashi appeared on top of the rooftop of the building via shunshin, he immediately noticed Hikaru, who is sitting at the edge of the concrete blockage wall of the rooftop.
For a moment, it was silent for the two of them.
"If I'm right, you're one of my cute little students, aren't you?" Kakashi was the one who broke the silence.
"Yes, " Hikaru replied.
"Then, can you explain what happened back there? I know for a fact that doesn't happen everyday, what did you do?" Kakashi asked him while narrowing his eyes in suspicion.
"Oh, that? Just a little trick, please don't be bothered by it. After all, it's your fault for being late, " Hikaru said with a slight smirk.