Going back to Nach's group at one of the fourth-floor restaurants:
While Nach and Hiro were finishing the Molotov cocktails, Saeko and Miku—along with Mitsushima and Asami—went back down to the ground-floor grocery section to gather more supplies, returning with six carts full of food and water, including some medicine and first-aid kits.
"So they're gathering glass bottles, alcohol, and oil this time," Nach said in response to Saeko's report about encountering more survivors who immediately ran away upon seeing her at the grocery section.
"They probably figured out what our group was crafting and decided to imitate us."
Like Saeko said, anyone who had seen a Molotov cocktail—even just in movies or anime—could easily guess what they were crafting from the materials Nach asked them to collect.
Perhaps we got a bit too excited crafting all of these, he thought, looking at the two dozen Molotov cocktails they had prepared.
It was only supposed to be a last resort in case Saki wouldn't die even if her head was cut off, or if she somehow obtained a regeneration ability that healed her cuts and wounds.
It could also be used as a means of self-defense by the young girls who couldn't fight—not against the undead, but against other survivors who might try to assault them while Nach and everyone else capable fought Saki.
But with Shido's group making Molotov cocktails as well, the same threat now applied to them, and Nach wasn't the only one who could comprehend this situation.
"Should we change our base, just in case they attack again?" Mitsushima suggested, proposing that they hide somewhere Shido's group wouldn't be able to find.
"Then let's move to the rooftop and barricade the door," Nach said, before suggesting another plan.
If it was deemed impossible to defeat Saki, Nach, Saeko, and Miku would draw her away from the shopping mall, giving everyone else time to escape using the helicopter.
"Wait… does that mean—" Mitsushima murmured, finally realizing Nach's mischief.
"Ta-da!"
Nach took the helicopter key from the inside pocket of his jacket and showed it to everyone as if it were a great magic trick—how he had gotten it from inside Shido's stomach.
"Pfft—hahaha!"
"Shido would be enraged once he finds out he swallowed a different key," Saeko said, unable to hold back her laughter like everyone else.
"Once the fight starts and Saki's attention is on us, you don't have to wait for us. You can fly the helicopter and head to Takagi Estate," Nach said, handing the key to Yui.
Yui, of course, had never flown a helicopter before. What she knew was only what Nach had taught her during their escape from Tominaga Hotel to the shopping mall. She wasn't even confident she could make it take off, much less land it safely. But if things took a wrong turn, Yui wouldn't have a choice.
"We don't plan on making a noble sacrifice, so don't make that face," Nach said, consoling Yui as if she were about to cry.
"But the helicopter won't be able to carry everyone, so some will have to stay," he added, asking for volunteers.
"You don't have to worry about us, sensei."
"We would rather give our place to the young ones."
The elderly couple spoke up.
In the original story of Highschool of the Dead, the elderly couple would commit suicide by jumping off the rooftop of the shopping mall before the undead broke through, caused by an idiot survivor attempting to escape outside.
The elderly woman also had a condition that required regular blood transfusions, which was why the couple believed they wouldn't last long in the chaos of the undead outbreak.
What they were suggesting now was no different from when the two old men, Tominaga and Hogosha, held the door on the hotel rooftop to hold back the undead horde—if only for a few seconds—so Nach could safely take off in the helicopter.
But if Nach had a choice back then, he wouldn't have let them sacrifice themselves.
"Even so, it's the responsibility of the young to look after our elders, so let us return the favor," Nach said, holding the hands of the elderly couple and reassuring them that there was no need for them to sacrifice themselves.
"You really are a good person, Nach-sensei," Saeko said, seeing his kindness that was usually overshadowed by his pervertedness.
"That's why Nach-sama deserves all the women he wants," Miku declared proudly, making Yui and Mitsushima awkwardly look away while hiding their blushing faces.
---
Arriving on the rooftop with their supplies and equipment, Mitsushima, Asami, and Hiro volunteered to stay with Nach, Saeko, and Miku to fight Saki, while all the girls, the elderly couple, and Morita would escape with Yui in the helicopter.
Takashi, on the other hand, was completely forgotten and left in the restaurant storage room.
"Don't do anything troublesome, missy," Nach said, lifting Tanuichi's face to look up at him, his right hand holding her chin.
"Yes…" Tanuichi replied, her voice trembling as much as her body as she felt Nach's intimidating and dominating presence.
After leaving Tanuichi to Morita's watch, Nach spoke to Misuzu and Toshimi next.
"Look after each other, both of you."
"Everything will be fine with the two of us together, right, Misuzu?"
"Mhm! We'll be best friends forever, Toshimi."
That's exactly what you said before kicking your best friend straight in the face, Nach thought, keeping an awkward smile as he remembered how Misuzu and Toshimi were supposed to die in the original story.
Right then...
"Nach-sensei," Saeko said, drawing his attention to the main road in front of the shopping mall.
The sight of an oil tanker truck entering the shopping mall parking lot brought nothing but a bad feeling to everyone.
Nach quickly grabbed the binoculars from his bag and looked at the truck, checking the driver.
The driver wasn't Saki or one of her undead, but the desperate, terrified look on the man's face was just as threatening as a horde of aggressive undead.
After all, the truck was heading straight for the shopping mall entrance at full speed, with no intention of slowing down.
—BAAAMMM!!!—
A loud crashing sound echoed throughout the shopping mall the instant the oil tanker truck smashed into the entrance.
—BOOOOMMM!!!—
It was followed by a devastating explosion that shook the entire building.
"Damnit—That girl really knows how to make a grand entrance."