Reincarnated as the Heroine’s Big Sister, but My Little Sister Fell for Me Instead - Chapter 14

It had been raining since morning.

The usual library. Lian and I sat facing each other, each reading our own books.

Being underground, the sound of the rain didn’t reach us. But the air was different. Damp, and a little heavy. The dark purple of the lighting seemed closer to orange than usual today.

“Sister.”

Lian called to me.

“What?”

“I want to do an experiment.”

“An experiment?”

“A magical interference experiment.”

“Ah.”

A magical interference experiment. Again, is it okay? That’s what Lian had said back then. I don’t mind, I had answered. But since then, neither of us had brought it up, and some time had passed.

“Alright.”

“Is it really okay?”

There was no reason to refuse. That experiment was useful enough that it could eventually be turned into a paper and published, and above all—

No, I decided not to think about it.

“Should I call Edvard?”

“Today, just the two of us is fine.”

Just the two of us.

I placed those words in my mind. As research, we needed to take records. But Lian said today was fine. It meant the experiment itself was the goal, more so than the records.

I also thought that was fine for today.

I closed my book. Lian closed hers.

We stood up and moved to an area with fewer bookshelves. It was near the center of the underground, where the lighting was most stable. We stood facing each other.

I checked the distance.

About a meter. Neither of us voiced that we were starting from a much closer point than last time.

“Do you remember the procedure?” I asked.

“I remember.”

“I’ll deploy the interference field first, so Lian, you apply light magic to its boundary—”

“I know,” Lian quietly interrupted.

Right.

For the two of us, it wasn’t something to confirm the procedure of at this point.

I raised my right hand.

I drew out my magic. Inward. A dark mist seeped from my fingertips, and the interference field spread around my body. Thin, yet dense. I increased the density compared to last time.

Lian raised her left hand.

Her light magic touched the boundary.

It was warm.

It was always like that. Every time Lian’s light magic touched it, warmth entered the darkness. I thought I’d get used to it, but I never did. Each time, I was a little surprised.

Lian took a step closer.

Her light magic entered deep into the interference field. It began to circulate. Light and darkness mixed, but didn’t extinguish. Neither vanished; they simply coexisted.

Another step.

We were within breathing distance.

There were eyes looking up at me. Calm eyes. But deep within them was something not calm. Something that was always there was showing a little more on the surface today.

Maybe it’s because of the rainy day, I thought.

On rainy days, Lian’s face was a little different. It had been that way since we were children. On days we couldn’t go outside, she would come to my room, and we’d read books side by side. The air of those days felt similar to today’s air.

“Sister.”

Lian said softly.

“What?”

“Today,” Lian paused slightly. “Can we go deeper?”

Deeper.

Deeper interference than last time. It meant mixing our magic more. In research terms, it would be measuring the depth of resonance.

But Edvard wasn’t here today. There were no records.

“…Alright.”

Lian took another step closer.

The distance vanished. Lian was inside the interference field. Her light magic was mixing deeply with my dark magic. What was supposed to be something outside our bodies—it became unclear where outside ended and inside began.

Lian’s lips parted slightly, as if inviting.

I closed my eyes as if falling asleep.

Lian’s lips touched mine.

They were soft.

I felt a hot breath. Lian’s breath. It trembled slightly. Whether from nervousness or something else, it transmitted through our lips.

Neither of us moved.

We simply touched.

Lian’s light magic entered deep into my dark magic. I could no longer distinguish whether it was our lips or our magic that was touching. It was warm. It wasn’t dark. It wasn’t cold.

It lasted longer than last time.

Neither of us moved. Within the interference field, light and darkness continued to mix.

We pulled away simultaneously.

I opened my eyes.

Lian was there. Her cheeks were flushed. But today, she didn’t flee. She looked at me with eyes straighter than usual.

“…The depth increased, didn’t it?” Lian said.

“It did.”

“Should we record it?”

“Not today.”

Lian smiled a little.

I dissolved the interference field. Her light magic slowly receded. But today, the lingering sensation was long. It took a while to fade.

After it faded, we both returned to our original seats. We opened our books.

For a while, we didn’t read.

The rain continued to fall. The sound that didn’t reach the underground—yet today, I felt I could hear it.

“Sister.”

“What?”

“Let’s do it again next time.”

I didn’t answer.

Instead, I silently turned the page of my book.

That was enough.