“So, for what reason are you taking me to this kind of place?”

In addition of an exaggerated att.i.tude, Scarlet looked around the surrounding with dissatisfaction.

Scarlet and the members of Amaterasu was led away forcefully into Nayuta Lab without even knowing the reason. Right now they were in confined situation inside Kei’s s.p.a.cious research room.

There was not even time to change clothes, so all members were in their pilot suit that showed out their body line distinctly. The suit was made to cling on the skin, so it was closer to being naked than wearing normal underwear or swimsuit. The shape of the breast, the depression of the navel, the chasm of the a.s.s, all of those spots were distinctly exposed.

Such charming bodies of four women were lined up in front of Hida Kizuna’s eyes.

……As always he was bothered where to look. Nevertheless, what was going on right now?

Even for Kizuna who was always got slaved around by his big sister’s unreasonable demand was feeling something out of place from Reiri’s action this time. It seemed that the other members were also similar, Aine and Himekawa also looked a little doubtful.

“You are Scarlet of Masters right? I’m the commander of Ataraxia, Hida Reiri.”

“The seventh flying corps of Megafloat West USA, Masters. I’m the leader Scarlet Fairchild.”

Scarlet looked up at Reiri with haughty att.i.tude. Her height was lower than Reiri. She was around 160 cm. Her body that was wrapped in conspicuous pilot suit looked well trained even seeing from outside. The slender and tightly flexible body gave off the impression like steel spring. Her red ponytail shook on her back. She threw out her chest haughtily but its volume was slightly small.

“So, Ataraxia’s commander-san. What in the world with this treatment I wonder? You have a reason that you can explain properly right? If not, this will become an international pro――”

“Wait, you! That way of talking in just to rude against the commander!”

Himekawa snapped at Scarlet’s att.i.tude, but Reiri raised her hand and stopped her.

“Himekawa, I don’t mind. Rather than that, this is the continuance of the story……I’m asking you to come here, is about Yuris.h.i.+a’s survival. I’m thinking of teaching you the answer.”

Reiri words changed the color of Scarlet’s eyes.

“I want to hear that by any means then. Just what in the world happened?”

“Wa, wait wait. Just wait, Scarlet and you commander too.”

As if unable to endure it, Yuris.h.i.+a raised both her hands trying to stop the two.

“Why are the talk become something with my death as the premise? I cannot understand this at all. Or else what? Am I a zombie or something?”

Scarlet glared at Yuris.h.i.+a.

“That’s why! I told you that Cross’s energy source is human life right!? Yuris.h.i.+a should have your Hybrid Count hit zero since a long time ago already! Or else what? Are you saying that you are hiding all this time without fighting?”

“There is no way that’s true right?”

Yuris.h.i.+a too began to look irritated.

“――Let’s speak from the conclusion first.”

All members present were waiting of the continuance of Reiri’s words with their breath held.

“The information about Cross using human life as energy is just a false rumor. It doesn’t have any basis as truth.”

“That’s a lie! There is no way that’s true. Because, I heard that rumor from above you know? Besides, this hastiness is strange no matter how you see it.”

Scarlet that snapped down at Reiri made her spoke coldly.

“Do you think we will be happy if someone spread suspicious rumors without basis? Just what are you scheming, planting needless terror and doubt in the student and civilian?”

There was a pressure that overwhelmed other person inside the sharp gaze that Reiri emitted. And then, those words were unusually hard and brutally threatening.

Scarlet unconsciously faltered from that intensity.

“I, I’m not, scheming anything at all!”

“What are you doing is the same as terrorism. You are intentionally spreading rumor that lead astray the heart of people and caused bad influence on the public order of Megafloat. If you are trying to speak of that matter once more, we will prepare to formally protest at the government of America.”

“Eh? Come on, stop that! I’m not really trying to spread rumor here.”

Reiri crossed her arm and stayed quiet, as if stating that the discussion was over already.

“Because, even the newspaper of West USA wrote that Yuris.h.i.+a died at Megafloat j.a.pan, it was exclusively talked……”

Reiri was merely glaring at Scarlet, pressing her to make a decision.

“Uu……go, got it okay! Geez, I’m not spreading any rumor at all anyway!

Even I just heard of that from somewhere! Besides, Yuris.h.i.+a is clearly alive right in front of my eyes, so even an idiot will know that’s a mistake!”

Scarlet lightly clicked her tongue.

“Really……so it was just a rumor. Aaaa, how stupid. Reaaally……”

And then, she talked as if spitting up.

“――That’s disappointing.”

Kizuna doubted his ear.

‘Di, disappointing?

They were comrade in the past……weren’t they? Isn’t she happy that Yuris.h.i.+a is actually alive?’

However, Scarlet’s eyes that were staring at Yuris.h.i.+a didn’t look happy of the reunion. Her eyes looked as if she was staring at the killer of her parent.

“You haven’t forget of what you have done to us before this aren’t you? I won’t recognize Yuris.h.i.+a Farandole. Are you listening? Fake hero-san.”

Yuris.h.i.+a knitted her eyebrows. Her eyes staring at Scarlet was slightly colored in sorrow.

“I don’t think it’s possible but, are you thinking that even now you are the ace of America? You are treated as dead in our place, so that’s the same as being nothing. There is no problem at all even without you in Masters, or perhaps I should say, there is no place for you to return after all this time.”

“……Is that so? I understand that.”

Yuris.h.i.+a nodded unaffectedly.

“――Wha-“

Looking at that behavior, Scarlet grinded her teeth with expression of anger.

“Wha, what’s with you! You are not angry after I’m speaking that much? Don’t you have any pride or honor?”

Yuris.h.i.+a’s accepted Scarlet’s vitriol like feeling a gentle breeze.

“Not really. You can say whatever you like.”

“Kuh……Yuris.h.i.+a, I’ll ask one more time. Why did you do something like that?”

Against Scarlet that obviously couldn’t suppress her anger, Yuris.h.i.+a brushed her off with cold calmness.

“……Something like that?”

Scarlet’s eyes twitched upwards. She walked briskly forward until in front of Yuris.h.i.+a and glared up at her face.

“Don’t play dumb! Because of your fault I――”

Yuris.h.i.+a sighed dismissively.

“Scarlet, is it okay if I talk frankly I wonder?”

“Sure, I’m asking you to speak since just now already! Answer quickly!”

“I don’t understand at all just what it is that make you so irritated.”

Scarlet’s right hand drew an orbit and stike at Yuris.h.i.+a’s chee――

That hand stopped just before it reached.

“Kuh……!”

Yuris.h.i.+a’s hand caught and stopped Scarlet’s right wrist.

Scarlet glared at Yuris.h.i.+a with eyes filled of hatred. Yuris.h.i.+a’s expression was calm, but her eyes were not laughing at all. Between the two, an atmosphere that could explode with a touch was drifting.

Scarlet forcefully shook off her hand and turned her back to Yuris.h.i.+a provocatively. She went outside the room with loud footsteps then.

Just what in the world was that?

“Hey, Yuris.h.i.+a. Just now, what is……”

“I’m sorry. I’ll go home first.”

Yuris.h.i.+a obstructed Kizuna’s words before she too headed to the exit.

‘――I don’t understand.’

But one thing for certain, something happened between the two of them in the past. Though he didn’t know what it could possibly be.

Ignoring the awkward atmosphere of the place, Reiri raised a frigid voice.

“The talk is over. You guys too return to the dormitory and rest.”

Amidst the gloomy mood, Aine and Himekawa also exited the room. Kizuna too was going to follow after the, but Reiri’s voice called at him.

“Kizuna, you remain here.”

‘Eh? Just me……wait, for what business?’

Even while feeling dubious, Kizuna returned into the middle of the research room. He could hear the sound of the door getting locked behind him. At the same time, Reiri sunk her body deeply onto the chair and looked up to the ceiling.

Even though he was intentionally ordered to remain, both Reiri and Kei didn’t really start to talk.

“……Err, Nee-chan. That thing with Yuris.h.i.+a and Scarlet just now……what’s going on between them? Do you know something?”

However it was like Reiri and Kei didn’t hear Kizuna’s statement at all. Reiri heaved a sigh and stared at Kizuna.

“Nee-chan, what’s wrong?”

There was not a trace of the pressure that pushed back Scarlet before this, she was making a tired face.

“Perhaps this is a good chance. Kizuna, there is something I need to tell you.”

“What is it, getting so formal like that.”

“This is about the talk of Yurisia dying if the Hybrid Count get used up.”

“Aah, the baseless rumor just now?”

Kei’s floating window appeared in front of Kizuna.

{I’m really amazed of West USA’s careless handling of information. We are going to formally state our protest of this.}

“Yeah, there is a limit even for a mistake.”

“Certainly, what a mistake that was.”

Reiri informed him with a heavy tone.

“The gear that use life as energy is not only Cross.”

‘…….

――Eh?’

“Zeros, Neros, Heart Hybrid Gears with ‘ros’ at the end of their name are all the same.”

‘Wha,

What is she blurting about?

Ros? She said.’

“Kizuna. Your Eros is also included.”

‘Wai,

Wait,

Just wait.’

“Err……Nee-chan. I don’t really get what you are saying. Using life as energy you said, what’s that mean?”

“That means that when your Hybrid Count become zero, you die.”

Reiri’s voice distinctly resounded inside the lab strangely.

The echo of the voice was vanis.h.i.+ng quietly.

And then only silence remained.

‘――Die?

If Hybrid Count become zero,

Me?

Also,

Aine,

Himekawa,

Yuris.h.i.+a too?’

“――Su,”

‘Such thing, just who can believe it.’

“What stupid……the joke is just too over, Nee-chan. Hey, s.h.i.+kina-san too, don’t join this kind of bad joke please.”

Just now, didn’t they say that this was only a rumor without any basis?

{I want you to listen calmly. Ros-series are special Heart Hybrid Gears.}

Special?

{Their basic performance are extremely high, they are also loaded with weapon of transcendence destructive power that is the Corruption Armament. Due to that――}

“The consumed energy is ma.s.sive. To the degree that it shaved off the user’s life.”

――Life.

{For example if it is the Heart Hybrid Gear that the Masters use, even if their Hybrid Count becomes zero, they won’t die. At worst, they will only faint and get send to hospital from overwork. But, the Ros-series that you all of Amaterasu are using not only absorbed your stamina. The mind power, willpower, all kind of energy that human possessed are taken. And then at the end――}

“They die.”

‘Tha,

That’s.’

“Yuris.h.i.+a was dispatched to j.a.pan was because Ataraxia is in the foremost line of Heart Hybrid Gear research. US army also noticed the exhaustion of Yuris.h.i.+a. In order to research the method to recover the decreasing Hybrid Count, Yuris.h.i.+a was sent to j.a.pan.”

He fell into hallucination that the world was distorting from this shocking information.

“Lies! No matter how you put it, there is no way such stupid weapon can e――”

“But that’s the truth.”

Reiri calm retort made his blood rose to his head.

“If that’s actually true, why does Nee-chan make us fight then!?”

Kizuna was driven by his boiling emotion, he came forward until in front of Reiri as if kicking on the floor. Kei’s floating window popped up at his nose tip as if blocking his way.

{Wait.}

{Calm down.}

Ignoring those texts, Kizuna pushed through the windows one after another. And then, he glared at his sister’s face at the distance where they could feel each other’s breath.

“The act of fighting the enemy itself shorten our life right!? By fighting to protect life, to protect the people, they are running at full speed toward their own death at the same time, isn’t that right!?”

“Exactly.”

“Whether we use Heart Hybrid Gear to fly, to fight, to do anything, each time we shaved off our own life! That’s just a suicide act! Without knowing anything about that, thinking that this is all for the sake of saving the world, we are――”

Reiri accepted Kizuna’s gaze straight ahead.

“That’s right. In order for mankind to survive, they are so to speak……sacrifices.”

Shock and fury, various kind of emotions were whirling inside Kizuna’s head, rubbing him the wrong way. Driven by that heat, he threw out the words rising in his heart as it was.

“The one sacrificing them is Nee-chan aren’t you!? You were ordering us to fight! That means Nee-chan was ordering us to die!”

Each time she was bathed with the piercing words, Reiri’s expression was chaning into a sad one.

“That’s right……I know about that and still made all of you to head into battle. It cannot be helped whatever you say about me. What I was doing was the same as trying to kill you all.”

Reiri’s usual resolute att.i.tude faltered. Her gaze was lost and she looked down.

“That’s just too inhuman! That’s not something good to do as a human!”

“That’s right! Even without you telling me, I know that already!”

Reiri’s emotion burst as if it was wrung out from her.

She raised her face once more and stared at Kizuna’s face. Inside her eyes, sorrow and pain were filling her so much, to the degree that it made him thought whether she would cry even now.

Kizuna’s heart was slightly shaken.

“Then, why――why are you doing that then!?”

“Then, what was I going to do!? The only thing that can oppose the AU’s magic weapon is just Heart Hybrid Gear. Using that, a lot of life can be saved! Despite that, the Heart Hybrid Gear is a weapon that use life as energy, it’s too inhuman and the pilot is just too pitiful, so we will stop using it. That’s why, all of you people of j.a.pan just die, am I going to explain it like that to all the people!?”

It was a sorrowful tone, as if she was becoming defiant, and yet it was like she was asking for help.

It was unthinkable for such tone to come from his sister that was always composed no matter what happened with her strong willpower.

It was unexpected.

Kizuna’s angered expression flinched from looking at that appearance of his sister.

What made him overpowered was not because of her appearance and behavior that he couldn’t usually imagine. He was overpowered by the weight of the discord that Reiri continued to fight alone inside her heart, of the strong pressure of the j.a.pan people’s life entrusted to her causing her worry and anguish that she harbored in her heart.

“――That, but, it’s mistaken to one-sidedly force someone to be a sacrifice!”

Kei that couldn’t bear to just watch threw a window between Kizuna and Reiri.

{Stop this already. Reiri is doing all she can to try to help all of you. That’s exactly why she doesn’t choose her method.}

“Doesn’t choose, the method?”

‘――Don’t tell me.’

“Is that…Heart Hybrid?”

Reiri dropped her gaze and answered with trembling voice.

“……While repeating real battle, we noticed the fact that Aine and the others’ Hybrid Count mostly doesn’t recover. And then one day, we discovered the data of Ros-series’ initial development. We were shocked when we saw that data.”

Reiri bit the inside of her mout.

“The reason was because Ros-series has the system that activates using the wearer’s life as energy. It makes sense that the natural recovery of Hybrid Count is slow. After all, the wearer is selling their life by pieces. And then when that energy is used up……they die.”

Reiri struck her fist to the wall.

“All of this! This is all mother’s fault! That person developed this kind of devilish system, then she didn’t say that fact to anyone and kept it a secret!”

Kaa-san.

Professor, Hida Nayuta.

The one who inserted the Core of Heart Hybrid Gear into him, the matter about mother flashed in his head.

――Kizuna. You are a good child aren’t you, do your best in the core activation experiment too okay?

――Like that, the experiment of gear’s materialization is going well.

He recalled how mother was always smiling kindly.

“Ka, Kaa-san, she……knows this matter……”

“Obviously! Just who do you think developed this thing! That person was aware of the Heart Hybrid Gear’s compensation.”

It was a complete change from her exhausted state of just now, Reiri exploded in anger.

“I was, when I was in the lab, the decrease of the Hybrid Count, and the recovery of it was no problem at all so……that’s why, perhaps Kaa-san,”

{There is a difference like earth and heaven in the energy consumption between the experiment and real battle. By the time we realized this fact, Professor Nayuta had already disappeared. However, it’s unthinkable for Professor Nayuta who is the developer to be unable to predict this.}

“Ku……”

By the time Kizuna arrived in Ataraxia, Professor Nayuta’s whereabouts was already unknown.

{After that, a mysterious mail arrived, information about Eros’s special ability and Heart Hybrid with other gear was written in it. This mail was most likely something written by Professor Nayuta who disappeared. And then we summoned the possessor of Eros that is Hida Kizuna here in great hurry.}

“If we just knew that Heart Hybrid Gear need that kind of compensation……no.”

Reiri made a self-depreciating smile.

“That’s just too hypocrite. After all I still give the order to sortie knowing this information.”

“Nee-chan……”

“I cannot protest even if I’m killed by you all. If this battle end and mankind survive, you can do anything you like to me then. But, Kizuna. Because of my, of our mother’s fault, innocent girls became sacrifice and fight, sacrificing their life at the same time, that fact can never be forgiven. The misconduct of blood relative has to be redeemed by the blood relative.”

His sister’s words resounded inside Kizuna.

Surely until now she had persuaded herself like that many times already. It resounded like that.

“I won’t let even a single sacrifice come out from among Amaterasu’s member. If it’s for that sake, then I’ll use any method. Even if for example――”

Reiri’s hand caressed Kizuna’s cheek.

“I’ve got to sacrifice my blood-related brother for it.”

‘――Is that so?

So that’s how it is.’

He could finally comprehend the reason why that intellectual and rational sister was insisting of such crazy method like Heart Hybrid. Why after all this time he was suddenly called back to Ataraxia. This was why he was forcefully made to do Heart Hybrid in what seemed to be unnaturally impatient means.

Everything was for the sake of saving the life of everyone in Amaterasu.

Kizuna turned to Kei as if he had noticed something.

“s.h.i.+kina-san, can the Core be taken out from everyone’s body.”

{Impossible. Once it had been installed, it’s impossible to take it out. The only chance to take the Core out, is at time when the wearer meet their death.}

In the end, this couldn’t be resolved until their death.

{However,}

Kei continued to type on the keyboard.

{If it’s Professor Nayuta, perhaps she know of some kind of method.}

“If it’s Kaa-san……”

Certainly, it was a possibility.

{Information regarding Heart Hybrid Gear isn’t all disclosed. Even now there is information that exist only inside Professor Nayuta’s head.}

“You are saying that inside her head, there might be a way to save us?”

{At the very least, we will understand the reason why the professor created this kind of system. Besides, there is a lot of puzzle in the professor’s action. After her disappearance, why did she disclose Eros’s system? The mysterious sender in Guam too, that was perhaps Professor Nayuta’s doing.}

‘Aah, now that she mention that……it was still unclear for what reason the Entrance seal system’s information was sent from Guam.

{If we can directly meet Professor Nayuta, we can ask about this. Perhaps we can also understand the reason of her action.}

“I don’t want to hear about her reason or anything.”

Reiri spitted out.

“Just who can understand something like the thinking of that person. No, I don’t even want to do that.”

Reiri’s resentment and anger toward mother was not something normal.

“Kizuna. With this, there is nothing that I hide from you anymore. I didn’t convey this fact to all of you……what will you do?”

“Eh?”

In other words, she was questioning him, this fact that the more Aine, Himekawa, and Yuris.h.i.+a fought, the more they shortened their life, would he inform this fact to them?

“That’s……”

Cold sweat flowed from Kizuna due to the difficulty of deciding that when this question was thrust before him once again.

Although he blamed Reiri before this, now that he was made to stand in that position, the weight of that choice made his brain stopped completely.

“N……”

No way he could say it.

However, if he didn’t say anything, the girls would merely make to fight, without even realizing that they were paying sacrifice. That was just too miserable of a story.

But, even if that truth was conveyed to them, the fact that Heart Hybrid Gear was consuming their life didn’t change. Even knowing that fact, surely they would still fight the same like until now?

Even the slightest doubt and hesitation, could become fatal in the fight against AU.

Not only that.

What if, they were crushed by terror and doubt, and became unable to fight?

Was the situation of the world was so kind, that they would be let to quietly stop?

For argument’s sake if they became unable to fight, in this situation, could other people forgive a possessor of Heart Hybrid Gear that didn’t fight of all thing?

The core of Heart Hybrid Gear couldn’t be taken out unless the wearer was dead.

If there was anyone that thought out to take out the Core, by disposing of the unusable pilot――.

“There is……no need to say.”

“Kizuna?”

“Certainly it might be cowardly not to teach them the fact. But――”

Kizuna clenched his fist and spoke resolutely.

“Everything would be fine if I just constantly keep everyone’s Hybrid Count in safe level. If I do that, the fact that their life is used as energy is the same as doesn’t exist.”

“Kizuna……”

“From now on I won’t doubt in doing Heart Hybrid, I won’t even hesitate. I’ll do everything I can. Just who cares of what other people going to think or talk about me.”

There was unshakable resolution inside Kizuna’s eyes.

“That’s why Nee-chan, you don’t need to worry your――wapuu……!?”

Reiri embraced Kizuna’s head and buried that head into her own chest.

“Don’t say anything else. We will do something about mother’s misconduct somehow with our hand. We will also save the future of mankind while we’re at it.”

‘So mankind’s fate comes second……as always the scale is just too big.’

Kizuna smiled with his face still buried into his sister’s large breast.

“Even so, as expected it’s necessary to look for Kaa-san isn’t it? Just as s.h.i.+kina-san said, perhaps she has some kind of method to resolve this.”

{We too are continuing to investigate of Professor Nayuta’s whereabouts. We also request cooperation for information with West USA, but we are still unable to grasp her existence.}

“There is also no guarantee that she will obediently listen to what we are saying when we find her.”

“I too……will look of any clue in my own way. Well, even the specialist searching for her cannot find anything, so I think it’s pointless but……”

‘Putting that aside, until when I need to bury my head into Nee-chan’s breast like this?’

For some reason his head was also stroked but……well, it felt good, so perhaps it was fine to let this went on for a little longer……somehow, it made him remembered his childhood.

{Putting that aside, how long are you two going to continue this sibling’s love scene?}

“Eh? No, this is just!”

Kizuna separated himself from Reiri’s chest in panic.

{I feel really left out for some reason.}

“Tha, that’s not it, s.h.i.+kina-san! Please don’t make fun of me.”

Anyway, Aine, Himekawa, Yuris.h.i.+a, he would constantly maintain their Hybrid Count in the safe zone. For that sake, he was prepared to use any kind of method.

Even until now, he intended to study about girl within limitation for the sake of his mission to do Heart Hybrid. But, that was still naïve.

In order to protect everyone’s life, he had to realize Heart Hybrid more effectively with high energy replenishment rate. And then, for that sake, he had to polish his technique to please a girl.

To achieve that, he wouldn’t mind even if he would be hated or scorned by those girls.

When everything ended, he would accept any kind of treatment.

Also, one more thing.

‘――About Kaa-san, when I meet Hida Nayuta.’

He didn’t know where on earth was she, but he would find her without fail, and then he would ask the secret of Heart Hybrid Gear.

Kizuna firmly swore so.