PrologueI—Monon.o.be Yuu—have a secret.
Three years ago, to protect my hometown from being destroyed by "Blue" Hekatonkheir, I made a deal with "Green" Yggdrasil.
Because the knowledge of power that Yggdrasil transmitted to me—data regarding weaponry from a lost civilization—was too vast in volume, I lost memories every time I downloaded.
My younger sister Mitsuki would surely feel sad if she found out about this, hence I kept it secret from her, because I did not want to see suffering on Mitsuki"s face—
But it was already too late.
I had even forgotten that Mitsuki was not my sister by blood. Even my precious feelings towards her... had been lost.
I am myself. Simply this alone would already hurt Mitsuki. At some point in time, I was already no longer my original self.
And it was actually just now that I finally noticed this myself.
I confessed this secret, which I had kept hidden in my heart until now, never disclosing to anyone at all.
I told the girl who should be the most precious to me currently—Iris Freyja—forcing her to shoulder the heavy burden I could not withstand on my own.
Inside the mildly rocking transport ship, in front of the cabin a.s.signed to me, I embraced Iris tightly as though crying out for help, telling her everything.
I struggled internally, trying my hardest to squeeze out words that sounded like a guilty confession.
Iris silently listened to me.
"Sorry for telling you this kind of thing out of the blue..."
After I finished, I apologized to her with a heavy conscience.
—What am I doing?
Stunned at my own weakness, an intense wave of regret surged in my heart... But time could not turn back.
"Hmm... You told me so much in one go, my mind is totally muddled."
Iris replied to me with a wry smile and wrapped her arms around my back.
Full of chagrin, my heart pounded in response.
"But if there"s one thing I definitely felt, it"s that you"re relying on me, Monon.o.be, so don"t worry!"
Iris separated from me and looked me in the eye squarely.
"This time, it"s my turn to help you, Monon.o.be."
Iris declared with clear determination on her face.
There was not the slightest hesitation in her eyes. She simply focused, staring at me.
"Iris..."
"This isn"t something to tell everyone, right? In that case, let"s go into the cabin to talk. I want to hear more from you, Monon.o.be, to think about what should be done."
Thus, we entered my cabin and sat down side by side on a bed, to continue the conversation.
Specifically, she asked me how I lost my memories and why I could not tell others—
Iris asked with an expression of unparalleled seriousness on her face while I answered all her questions honestly.
Finally, she stopped asking questions and the cabin returned to silence.
I saw Iris silently stare at the ceiling for a while before whispering softly:
"For you, Monon.o.be, falling in love with me... must be the most painful for you."
"No, that"s—"
I reflexively tried to deny what she said, but words failed me mid-sentence.
Because Iris was right on target. What made me feel the worst was that I had betrayed my past self—I had betrayed my promise with Mitsuki.
—Even after becoming siblings... I will still love you more than anyone else, Mitsuki, and we will get married when we grow up.
I had apparently made such a vow to Mitsuki during our childhood.
Having forgotten such an important promise, falling in love with Iris, I was no longer the Monon.o.be Yuu whom Mitsuki knew.
Hence, I could no longer bear it. I felt intense guilt for continuing to pretend to be Monon.o.be Yuu, which was why I revealed everything.
"Monon.o.be, you don"t need to force yourself to deny it, because even if it"s true, I"m still very glad."
"Glad...?"
Unable to understand Iris, I asked her. Iris leaned herself over and rested her head on my shoulder.
"Yes, only because it"s the current Monon.o.be, I feel like doing this... The current Monon.o.be loves me—This means that our feelings are mutual, right?"
"Well, I guess you"re right..."
"Then it"s fine. I feel very happy just knowing this alone."
Iris smiled with blushing cheeks, looking up shyly at me.
My guilt-filled heart instantly felt slightly warmer.
"Monon.o.be, now is not the time to agonize or feel lost. Let"s think together about the future."
"The future?"
"Yes, we must find a way to get your memories back."
Hearing her say that, my jaw dropped in surprise.
I could not understand. I really could not comprehend how Iris could say this so nonchalantly.
"Are you serious?"
"Eh? Yes, of course I"m serious. Do you think it"ll be very hard, Monon.o.be?"
"No, this isn"t an issue of easy or hard... You do realize what it means, right? If by any chance, I retrieve my memories—"
There would be no harsher reality than that, so I was unable to finish my sentence.
But Iris seemed to realize what I wanted to say. She smiled a little sadly.
"I know, then you won"t be the current Monon.o.be anymore... But it"s okay, because I"ve decided to help you, Monon.o.be."
Iris was making herself very clear. Even if it might mean losing her current happiness, she would still go ahead.
How could she become so strong?
Thinking back, she was like this already from our first encounter. I was never able to understand Iris" style and behavior. Whether in a good sense or a bad sense, she was always beyond my prediction.
Probably because she was so impossible to understand... That was why I fell in love with her.
I stared at Iris" face, mesmerized, only to see her slightly averting her gaze shyly.
"Umm... Although I made such a bold promise, I actually haven"t come up with a specific plan, sorry."
"Don"t apologize. Thank you. It"s the thought that counts."
Although I did not think there was a way to recover my memories, I still thanked her sincerely.
"Oh, but there"s one thing bothering me a lot. Although you don"t seem concerned about it, I find it quite surprising..."
"What"s bothering you that much?"
"Monon.o.be, you lost your memories because you entered a contract with Yggdrasil, right?"
"Y-Yeah, but that"s the unavoidable price—"
I was just about to tell her how ma.s.sive the information I was forced to download was, but Iris interrupted me. With intense worry, she said:
"Is that really true? I don"t think so. Why aren"t you wary of Yggdrasil, Monon.o.be? That thing is humanity"s enemy... A dragon, you know?"