Going back in time a little.
After the Senba siblings cleaned up the Dog-Class raybeasts, the students gathered the crystals of the raybeasts.
The glowing organs were inferior to photons and fake photons, but they could still be used as an energy source. They were often used in places that couldn’t afford fake photon or in low-powered devices.
The students took care not to damage the goods as they retrieved them. After all, the better the condition the crystals were, the higher they would sell.
“Look at all the crystals! We’re rich!”
“With this much we’ll definitely secure the top class positions.”
All hints of worries were gone from their faces as they happily gathered the crystals.
When they held their fosters over the glowing organs, the glowing organs disappeared into their fosters like it was melting into it.
They put away their weapons too since they would only get in the way while gathering the crystals.
“They’re too lax.”
“It’s their first big victory, give them a break.”
Although the two siblings looked fed up as they watched the students, they let them do as they please.
The reason for that was because they knew they were so elated that they wouldn’t be any useful even if they asked them to get back to work.
“…I wonder if we were like that at first too.”
It wasn’t an odd sight for newbies to act like that, though. In fact, the siblings themselves have also had their moments of negligence.
The older of the two asked the younger in a rare sense of nostalgia, but the latter denied her.
“Nah, during our first patrol, you just kept chasing after the raybeasts.”
Stopping you was seriously a pain, the younger sighed.
Reminded of her embarrassing rampage, Youko went beet red and warned her brother to keep quiet.
“You’re the younger one. What are you acting so cheeky for?”
At the same time, she took his head under her arm and wrestled him.
“OWWW! I give! I give!
Seriously, you’re too violent. That’s why I can’t help but act cheeky sometimes.”
As soon as the headlock started, Yousuke immediately tapped out on her shoulders and ran.
But Youko puffed up her chest, not in the slightest bit guilty.
“I’m the big sister, so it’s only natural I’m strong. I’ll protect you, so make sure to work hard.”
“Sure, sure… Even though we’re twins… You just happened to get out a little faster, so why am I being treated like this?”
“Did you say something?”
She obviously heard him, but he didn’t bother pointing that out.
The so-called ‘imprinting’ from their long years together wasn’t just for show. The younger brother could never win against the older sister.
“The Senba senpais sure get along well, huh. My little brother never listens when I scold him.”
“It’s because they had to support each other without their father.
What beautiful sibling love! What beautiful familial love! …I wonder if we can use this as topic this summer?”
“They’re real people, so please stop! At this rate, we’ll never see the end of this!”
Sensing that things were about to go down an improper route, one of the girls stopped the rest of the girls and urged them to focus on gathering the crystals.
The male students had no idea what the women we’re talking about, so they just tilted their heads in confusion for a moment before gathering the crystals again.
“Hmm, huh? Why is there a cleaning robot at this time?”
Although Yousuke wasn’t privy to the disturbance going on, he still thought something was odd when he caught the cleaning robot from the corner of his eyes.
The quadrangular-prism-shaped cleaning robot was approaching.
The robot itself wasn’t strange by any means. It was a normal sight in this city, after all, but they shouldn’t be out during this time since there’s a chance they could get caught with the raybeast battles.
“Is it broken? I’ll take a look,” Youko said.
“Alright. I’ll keep watch here,” Yousuke replied.
Another part of their duty was to check when something belonging to the city might be broken. And with the cleaning robot being a common sight, Youko put her guard down completely as she approached it.
“Garesto Academy 2-B, Senba Youko.
Under the authority of the public morals committee, I order you to switch to maintenance mode.”
Youko waved her foster in front of the robot’s camera.
Normally, the robot would stop there upon receiving data from her terminal and from her voice.
“Pi pi, Ga.
Earthling confirmed. Traitors will not be forgiven.”
But the cleaning robot said something unbelievable instead, and then in the next moment, it leaped toward her.
Everything happened so fast and unexpected that Youko failed to react at all.
Before she knew it, the robot had slapped her foster away and had tied her up with a rope.
“A rope!? Something like that can’t—!”
She had a strength rating of AA+. She could easily brute force her way out of a normal rope like that.
But before she could, the cleaning robot threatened her.
“Warning, if the rope is cut, this unit will immediately self-destruct, giving rise to an explosion with a radius of 100 meters…”
“What!? You’re kidding!”
Youko turned around and looked at her comrades.
Her kouhais were in cloud nine as they gathered the crystals, while her younger brother, Yousuke, was keeping watch for any raybeasts.
If an explosion with a radius of 100 meters were to occur here, they would surely get caught in it.
She couldn’t act rashly.
“10 seconds to explosion. 19, 9, 8…”
But then the robot heartlessly started counting down to its explosion.
Apparently, it had been programmed to explode by itself even without external influence.
Yousuke, protect the others! It’s going to explode!”
That desperate cry finally made the younger brother realize that something horrible was happening.
Youko figured he probably wouldn’t make it in time, so she took the rope and carefully dragged the robot along.
At the very least, she wanted to move the robot to a corner without any building or people.
I have to protect my little brother! I have to protect Yousuke!”
At this point, she wasn’t even thinking about her life.
The only thing on her mind was the younger brother who endured the past 8 years with her.
She was the older sister. She had to protect him.
“Wait, Nee-chan! Your foster!”
The younger brother, Yousuke, could tell what his sister was planning, but she didn’t have her foster.
Without it she wouldn’t even be able to put up a barrier.
Of course, surviving a pointblank explosion even with a barrier would still take a miracle, but it still beat nothing.
“5… 4… 3…”
Unfortunately, it did not seem he would make it. There just wasn’t enough time to cover the distance.
But Yousuke refused to accept that. He would not just watch his sister be killed in front of him without doing anything.
Invoking a skill, Yousuke strengthened his body and ran.
An agility of AA+ was indeed not just for show.
It was only an instant, but he was already near enough to reach her shoulders.
But there wasn’t even a second left until explosion. There wasn’t even enough the time to use his strengthened body as a shield to protect her.
If not for the rope, he could have taken her and jumped back, but alas… There was no time to cut it.
But still he pushed forward. There was no reason to it anymore, he simply wanted to protect her.
And so did she to him, as she – in the last moment – spread her arms to try and protect her younger brother.
Just as the count was about to hit zero, the two siblings desperately sought to protect each other.
It was because of that the two of them were able to see the beautiful glitter of an aurora, then in the next moment, the rope was cut, and before the resulting signal could even reach the robot, a black something sent the cleaner robot flying into the sky.
As that black something yelled and covered the siblings, the rest of the students got down on the ground.
In the next instant, an earth-shaking explosion blew up in the night sky, sending shockwaves throughout the city as it dyed the black of the night in its red.
As the flowers of explosion bloomed in the night sky, the students down below looked up at it with blank amazement.
“Y-You’re kidding… He actually sent that thing over a 100 meters up into the sky in that instant!?”
While everyone was shocked by the explosion, Yousuke couldn’t help but be suspicious of the person covering him despite his shock.
It was only understandable. After all, they were this close, and yet he couldn’t make out this thing’s shape.
That suspicion didn’t last long, however, for immediately after he turned to his sister and shook her shoulders.
“Nee-chan!? Nee-chan!? Are you alright!? Are you hurt!? Does it hurt anywhere!?”
I just hit my back a little when I was pushed down. But forget me, what about you, you idiot!?
What were you thinking doing something so reckless!?”
“Hahh!? Are you actually seriously scolding me now of all times!?”
As the pair of siblings shifted into their usual routine, the black something stood up and moved away.
Although it could be inferred from his movements that he was looking at them, it was hard to make out his image. Yes, just like a picture out of focus.
The only thing for certain was that there was a white mask atop the area where his face probably should be.
“Ah, I don’t know who you are or where you’re from, but thank—”
Yousuke was suspicious of the figure, but Youko simply thanked him.
No matter how suspicious the black figure was, there was no denying that he’d saved them.
So she figured she should thank him first. What happens later is a matter for later.
But before she could finish her sentence, the black something apologized.
Naturally, not even Yousuke expected that they would be getting an apology instead, and the both of them were understandably confused.
“I don’t have the right to be thanked. All of this is due to my negligence. So, sorry.”
That was all the black something said before it moved and probably turned around.
It was so hard to make out the figure that it was difficult to even tell if it was facing front or back.
But since the mask couldn’t be seen anymore, then it had probably turned around.
“I’d like for you to contact the student council and the peace preservation department.
Tell them that there’s a possibility that bombs guised as cleaning robots are moving without photon.
Inside them is a huge amount of gasoline and gunpowder – I smelled it, so probably – Tell them to disassemble them carefully.”
The black something ordered the siblings like that without turning around.
The siblings quietly listened and then nodded as the black something spoke. They knew nothing of it. Not its gender nor its age, but when it turned around for the last time, it seemed to be smiling. At the very least, the part where the mouth probably should be seemed like it was smiling.
“You have a wonderful relationship. Treasure it.”
The voice of the mysterious figure was gentle like the caress of the wind.
And like the passing of the wind, as soon as it said its piece, the black figure vanished.
Originally planned to finish this chapter here, but looks like it’s a lot longer than I expected. Third part next week.