Fire Release: Heavenly Prison

As for why Kira went to Hiruzen? It was because as long as the person behind this wasn't Danzo, then that person would be heavily punished. And if it actually was Danzo, then Kira had other plans. 

When Hiruzen heard Kira's version of the story, he called the anbu black ops and asked them one question. 

"Where is Raichi?" 

One of them took a step forward and began speaking, "I'm the one who was tasked to spy on him and he's currently in his hou- no he suddenly stared running." 

There was silence for a while before he began to speak once again, "He's running towards... the place where your student, Orochimaru is doing his experiments at."

"Okay, you're dismissed. Continue keeping an eye on him." he said and once the anbu were gone, he turned to look at Kira.

"This is something that only the adults should be involved in. You should go back home."

Kira gave him an angry look but didn't refute his words. Instead, he talked about his bugs. 

"Sensei, I heard about the Root from my grandpa and even though I have no plans on joining that organisation, I heard that they have really nice labs for experimentation. If it's possible, could you let me use those labs?" he asked, not mentioning the fact that the root was under someone else's control. 

"Come with me, we'll talk while we run." Hiruzen said as he jumped out the window and began running over the buildings with Kira right beside him. 

He glanced at Kira and said, "Why not just use the labs that are under me?"

"They're good, but I feel like one of the three legendary sannin, lord Orochimaru has way more experience and knowledge when it comes to working on living things like snakes." he said, stopping himself from saying the word; humans. 

"Fine, but it'll depend on the situation there. For now, just go back home and come talk to me tomorrow." Hiruzen said, to which Kira replied with a nod and used Flying Raijin to teleport back to his room. 

*****

Once outside the Root Headquarters, Hiruzen glared at Raichi, "Why didn't you come to me first?"

"Because I feared that you'd let him go with a light punishment. And that's exactly what happened! You..." Raichi growled angrily, but stopped himself right before he was about to curse the man in front of him. 

He took a deep breath and with a calm voice, spoke "I wish to resign from the Anbu black ops. Permanently."

Hiruzen nodded, "Request granted. From tomorrow onwards, you will not be in charge of your team. Kira will be learning about his clan's bugs under Orochimaru's mentorship and Sachi... I'll assign her to a different team."

"This is... WHY?! For the first time, I found talented kids to teach and you take them away from me? Just what do you have agains-"

"With such uncontrollable emotions, you're not fit to be a teacher. You're dismissed." Hiruzen said sternly before walking away, leaving Raichi standing alone in the empty street, feeling lost and abandoned. 

He stood there silently for a few minutes before he began walking and he wasn't walking towards his house. Usually, he liked the peace when he walked alone at night, but this time, he felt different. 

A few minutes later, he stood in front of the Aburame clan's main gate and looked at the guards that were stationed there. 

"I want to talk to my student. Go and tell Kira to come here?"

The guards looked at each other's faces and nodded, "Okay, please wait here until I get him."

Raichi gave him a curt nod and silently waited, only to see the guard coming back alone. This made the frown on his face even more deep, as sadness welled up in his heart. 

Did his student did not want to talk to him anymore? Would everything end like this after spending almost a year together, taking up hard missions and completing them all with a 100% success rate? 

"Sir Uchiha, Kira said that it'll be better to talk inside. Would you like me to escort you inside?" the guard asked politely. 

"Oh." Raichi replied, feeling a little foolish for overthinking things. The news of him leaving the team wouldn't have reached his ears so soon after all. 

He was then escorted by the guard until they reached Kira's house and was dropped off at the door. 

"Sensei, why did you want to meet me? That too at a time like this... is it that important?" Kira asked as he opened the door and let his sensei in. 

Raichi didn't want to tell him that the team had been disbanded. He felt like there was a lump in his throat that was preventing him from speaking. 

"It's nothing too serious...." he muttered and then steeled his mind before speaking about the truth, "Actually, on the orders of the Hokage, the team will be disbanded. Sachi will be put into a random genin team and he wants you to learn from one of his other students whose name is Orochimaru. 

It's just that, before we parted ways, I wanted to teach you one of my most prized jutsu."

In truth, he never made any plans like that and was simply blabbering whatever came to his head. 

"Oh... that old man does whatever he wants huh?" Kira muttered, making sure that Raichi heard him before he talked about the Jutsu, "By the way, which Jutsu do you plan on teaching me?"

"It's a juinjutsu called Heavenly Prison. It's a fire release."

"Fire Release... Heavenly Prison, huh?"