Hueco Mundo, the World of the Living, and Soul Society.
The three worlds formed a lid above Hell, keeping the worlds from falling into it.
And the thing that connected those three worlds was the soul.
When souls died in the World of the Living, they were either devoured by Hollows and entered Hueco Mundo, or sent off by Shinigami Soul Burial and entered Soul Society.
Souls perished in Soul Society and Hueco Mundo, then returned once more to the World of the Living.
The souls flowing through that cycle were like glue, binding the three worlds together.
Hollows that possessed the ability to open Garganta could move freely between all three worlds.
They belonged to the very best kind of glue, the kind with both the strongest adhesion and the best flow.
With the Hōgyoku, Sōsuke Aizen had already brought that finest glue under his command.
Whatever he planned to do next would be much easier because of it.
As Muten Natsu listened to the teacher's voice in class and looked out the window, he thought back on the information Kisuke Urahara had shared.
He still could not determine Sōsuke Aizen's ultimate goal.
But one thing was certain. Muten Natsu, who possessed the Hell Flames, could not possibly stay out of it.
Whatever Sōsuke Aizen intended to do, it would inevitably involve him.
Everything before his eyes might well vanish completely into Sōsuke Aizen's scheme.
"Orihime." Chizuru Honshō leaned in beside Orihime Inoue with a mysterious look, lowering her voice under Tatsuki Arisawa's wary stare. "It feels like the world's about to end."
"Huh?" Orihime Inoue blinked in confusion. "How do you know?"
"Isn't it obvious?" Chizuru Honshō glanced in Muten Natsu's direction. "Muten-kun is actually paying attention in class today."
Rukia Kuchiki: "..."
Something like this had happened back at the Shin'ō Academy too. The moment everyone saw Muten Natsu not sleeping in class, they felt like something huge was about to happen.
Then again, it really was something huge.
Just who knew what was happening over in Soul Society...
"Hey! Which classroom is it again?"
"I don't know."
"Wait, didn't you write it down on a piece of paper before we left?"
"Ah... I can't find it."
"You can't find it? Hey! What the hell are you doing?"
"Stop arguing! Can't you just use Reiatsu to check?"
"But this is my first time wearing these things, so I'm not very good at controlling my spiritual pressure..."
"If you're that dumb, then I guess I can't blame you."
"I'm not dumb!"
"These clothes are way too tight."
"Then do what we did and stop tucking them in!"
"What kind of stupid thing is that to say? If I did that, how am I supposed to stick my wooden sword in my belt?"
"That's exactly my point. Why are you carrying a wooden sword at all?"
"Because they won't let us bring real swords!"
"Why not?"
"Because it's the law! The law here!"
The noisy voices echoed through the hallway, mixed with a jumble of footsteps.
"You're all too loud!"
"If you don't want to attract attention, keep your footsteps lighter!"
"Yes!"
"Yes!"
"We're here, this is the classroom! Hey, open up!"
With a clatter, the door to Class 1 Year 3 was yanked open under the wary stares of the students inside. Five people who looked thoroughly suspicious stood in the doorway, all wearing school uniforms.
"Yo, Muten!" Renji Abarai, with his red pineapple hair, called out in greeting. "Long time no see!"
His hair color alone was loud enough, and with those exaggerated eyebrow tattoos and the ink spreading down his neck and shoulders, Renji Abarai did not look like a good person in the slightest.
Standing beside him, the bald Ikkaku Madarame with red eye shadow looked even scarier. With a wooden sword stuck at his waist, he looked like someone who had just come back from a fight and still had not calmed down.
Yumichika Ayasegawa, who had actually tied his necktie properly, looked fairly well behaved by comparison, but his dramatic feathered decoration still gave off a strange impression, making it hard to tell his gender at a glance.
The other one wearing a tie was Tōshirō Hitsugaya, but he was so short that next to everyone else, he looked like an elementary school student.
Beside him, Rangiku Matsumoto, with her big blonde waves, looked around curiously. The dangerously deep valley her school uniform shirt could not fully restrain surged and swayed as she turned her head.
"Orihime~!"
"Rangiku-san!" Orihime Inoue called out in delight. "What are you doing here?"
"It's a mission, of course~" Rangiku Matsumoto answered with a smile.
"Hey, hey... who are these people?"
"Muten's accomplices... no... his group... no, that's not it either..."
The class buzzed with whispers.
"That bald guy is terrifying..."
"Who's the redhead?"
"Are they delinquents?"
"So big!"
"If they know Orihime, they probably can't be that bad..."
"Does birds of a feather really apply here?"
"He even dyes his hair..."
"He really doesn't seem like a good guy."
"Bald."
"That head is so shiny."
"Not a single hair on it..."
The veins standing out on Ikkaku Madarame's completely exposed scalp became especially clear.
"Hey! Whoever just called me bald, get out here! I'll cut you down!"
"Tatsuki!" Rukia Kuchiki grabbed Muten Natsu's and Orihime Inoue's hands. "Please help cover for us!"
Grabbing one in each hand, Rukia Kuchiki herded Muten Natsu, Orihime Inoue, and the five visitors from Soul Society out of the school like sheep, then brought them back to Muten Natsu's house.
["We're preparing for a full battle against the Arrancar. Go to the World of the Living and join them."] Renji Abarai repeated Kuchiki Byakuya's words. "That's what the captain said."
Renji Abarai's feelings toward Kuchiki Byakuya right now were honestly complicated.
If you called it betrayal, then his goal and Kuchiki Byakuya's were actually the same.
But if you said it was not betrayal, then he really had crossed blades with Kuchiki Byakuya.
"The drinks are here~" Orihime Inoue brought out juice for everyone. "This is the first time we've had so many people at home."
"Thanks..." Renji Abarai took a drink. "Muten, how come you barely have any friends over here?"
"I don't know." Muten Natsu took the Calpis Orihime Inoue handed him. "Probably because I don't have eyebrow tattoos."
Renji Abarai bristled.
"You got a problem with my eyebrow tattoos? Huh?!"
"No." Muten Natsu gave him a glance. "I'm speechless."
"Grrrk..." Renji Abarai started grinding his teeth.
"It really is the first time we've had this many people." Rukia Kuchiki felt the room was a little dark and casually turned on the light.
But there were too many people, and the light was blocked.
Muten Natsu dragged Ikkaku Madarame directly underneath the ceiling light in the middle of the living room.
The whole room brightened up.
"Genius!" Rangiku Matsumoto clearly noticed the change in lighting and gave him a thumbs up.
Ikkaku Madarame: "..."
Renji Abarai explained the reason they had come.
"With the strength of the Arrancar showing up now, Rukia alone isn't enough to handle things here anymore. So the Captain-Commander sent us over to help."