I'm Female Lead In Their World: Living in the High School of the Dead

"Everyone, hurry! I guarantee you will make it out alive!"
"Okay, sensei!" The students shouted back, their voices mingled with fear and urgency as they darted toward the bus. However, amidst their frantic escape, a few of them stumbled, their courage wavering under the threat of the undead that loomed close.
(Despite what I said, I wonder if they will even make it to the bus.)
Nishinoya, finally summoning every ounce of strength, ran with all his might. But in his haste, he miscalculated his foot placement and tripped, falling hard to the ground.
"Sensei, I sprained my ankle! Help!" Nishinoya cried out, panic creeping into his voice as he reached for Shido's leg, his eyes wide and pleading.
"Oya? Is that so? Then it's the end for you." Shido's smile was disturbingly cheerful as he lifted one leg, preparing to deliver a punishing kick.
"Sensei?" Nishinoya's heart raced as he watched Shido's leg aim towards his face, a sense of betrayal washing over him.
In the split second before impact, Niikaz stepped in. One of her leg stopped beneath Shido's leg that about few inches away from Nishinoya's face.
"What are you thinking you're doing to Kazu's friend?" Her voice was low, laced with fury, as she shot Shido a death glare that could pierce through the thickest fog of cowardice.
With a swift motion, she wrapped her fingers around Shido's neck, lifting him effortlessly off the ground. The panic in his eyes contrasted sharply with her steely resolve. "W-who are you? How dare you do that to your teacher!?" Shido struggled, his hands clawing at her wrist in a futile attempt to break free.
"Niikaz!" Nishinoya looked up at her, tears threatening to spill over.
"You misunderstand! I'm about to save him, I swear!" Shido gasped, desperation creeping into his tone.
"Do you think I'm deaf and blind?" Niikaz tightened her grip, feeling Shido's air wane as his face turned a shade of blue. She released him, allowing him to crumple to the ground, gasping for breath. "Next time, I will truly kill you! Got that?" she warned, her voice cold.
She turned to Nishinoya, lifting him onto her back with surprising gentleness despite the chaos surrounding them.
(I have to calm down. It's not his time to die yet. Even if his personality is shit!... Urgh, calm down. Calm me down!) Niikaz fought to control her emotions, her heart pounding against her ribcage like a frantic drum.
"Wait for me!" Shido called after them, scrambling to his feet as he rushed to catch up with the others.
Once they reached the bus, Niikaz quickly placed Nishinoya in the first seat. She took a seat beside Kazu, her heart still racing from the confrontation. Shido slumped into the back, muttering to himself, a mixture of shame and anger on his face.
"Sensei, let's go!" Takashi urged, looking around to ensure everyone was inside.
"Okay!" Marikawa pressed the gas hard, determination set in her eyes as she steered the bus towards the gate, swerving to avoid the undead that were closing in.
As they neared the gate, Marikawa's heart sank. Hundreds of the undead swarmed the entrance, their lifeless eyes fixated on the bus. "They are not human, they are not human!" she yelled, her voice rising in fear as she pressed the gas to its limits.
In her mind, she focused on the simple truth: They had to escape, no matter the cost. She drove the bus in a zig-zag pattern, dodging the undead as they collided with the vehicle, their bodies crumpling beneath the wheels.
The bus rammed into the gate, the sound echoing like thunder, and it drifted around the corner, leaving the school behind and heading into the city.
*Inside the bus, as the chaos calmed down for a brief moment*
Nishinoya laid across two seats, trying to ease the pain from his sprained ankle. The adrenaline from their escape slowly ebbed away, leaving behind a sense of fatigue that clung to the air like a heavy fog. Behind him, Okada rested his head back, eyes closed, trying to reclaim a moment of peace amidst the chaos.
Across from them, Kazu and Niikaz exchanged worried glances. Kazu was still processing the events that had just unfolded, the weight of responsibility heavy on his shoulders. "L-Looks like we made it. Urgh, my heart still won't calm down." Okada finally breathed out, relief washing over him. But it was tempered by an underlying fear of what lay ahead.
"Nishinoya, are you okay? Can you handle it? Marikawa-sensei is driving right now, so we'll treat this as if we've stopped somewhere safe." Kazu looked at him, genuine concern etched across his face.
"I can manage just fine. So don't worry, okay!" Nishinoya forced a smile, but the pain in his eyes betrayed him.
"Luckily Niikaz came to save you. But Niikaz, how did you know that Nishinoya was about to fall?" Okada asked, a hint of curiosity sparking in his tone.
"Hmm? I don't know. I just ran toward him without thinking and suddenly saw him trip, so I helped him out. That's all," Niikaz shrugged, tilting her head innocently, but a small smirk tugged at her lips.
"I-I see. Thank you for helping me out there. A-as for Shido-sensei... I really dislike him," Nishinoya said, his frown deepening as anger bubbled beneath the surface.
"Hmm? What do you mean, Nishinoya?" Kazu tilted his head, genuinely confused.
"You know what? He was about to kick me and leave me behind to get eaten by them!" Nishinoya's voice trembled with indignation.
"What!?" Okada's eyes widened in shock, disbelief etched on his face.
"Hmmm!" Nishinoya nodded emphatically. "I was saved thanks to Niikaz. Otherwise, I would have become one of them!" His body shook at the thought, the vivid image of being devoured by the undead haunting him.
"That son of-" Kazu growled, the fire of anger igniting within him. He started to rise, ready to confront Shido, but Niikaz caught his arm.
"Why? Why did you stop me?" Kazu asked, frustration evident in his voice.
"I know you're angry, but it's not the time to punch him. It will only create more problems. Besides, I already choked him for you," Niikaz said, winking playfully as she tried to lighten the mood.
Kazu's expression shifted from anger to surprise, his mind grappling with the unexpected reveal. "Wow, Niikaz, you are really badass!" Okada exclaimed, a mixture of admiration and awe in his tone.
The bus suddenly jolted, snapping them back to reality. "The city!" one of the students shouted, drawing their attention outside.
Black smoke spiraled into the air, casting a dark shadow over the deserted streets. It was a ghost town, the once-bustling city now eerily silent, a haunting reminder of what had transpired.
"Look here!" The blond boy, Tsunoda, interrupted, his voice cutting through the tension. He was a delinquent, his hair shaved on both sides, a tough exterior masking his own fear. "We will never make it if we keep going! Why do we have to do whatever you guys planned? You all decided to go back to the city without asking us. Couldn't we just look for a safe place inside the school?"
"That's right! We should find a place to hide, like the convenience store we just passed!" another voice chimed in, echoing Tsunoda's sentiments.
"Then why did you follow us? Just keep hiding at the school like you said before," Niikaz interrupted, her tone monotone yet cutting.
"Who says that?!" Tsunoda retorted, his annoyance growing as he leaned closer to her.
"Ni-Niikaz." Kazu's voice trembled slightly as he looked at her, concern etched on his face.
"Come on, get the hell out of the bus and go back to the school!" Niikaz dismissed him, her eyes focused outside as if searching for something that wasn't there.
"What did you say-" Tsunoda stepped closer, trying to intimidate her, but Marikawa pressed the brake hard, causing him to stumble slightly.
She unfastened her seatbelt and turned around, her patience fraying. "Enough! I can't concentrate on driving with all of you yelling!" she snapped, her frustration palpable.
Tsunoda's eyes widened as he focused on her. "What the hell?!" he exclaimed, momentarily distracted by her form as she leaned forward, her movement revealing her figure.
"Then what do you wish to do?" Saeko asked, her calm demeanor a stark contrast to the brewing chaos.