When I opened my eyes, the first thing I heard was the sound of waves crashing against the shore.

  Still a little sleepy, I put on my uniform and made a light breakfast before leaving for school.

  “How I would love to stay in bed all day...” I muttered to myself.

  As I left the house, the heat of the sun was already beginning to be felt, mixed with the salty, humid air characteristic of Ryushio.

  As I walked along my usual route, I noticed that the sea was particularly crystal clear. I could see the fish swimming among the corals with unusual clarity.

  I paused for a moment to enjoy the tranquility when, suddenly, something caught my attention. A strange shadow moved quickly underwater, scattering all the fish. A shark? Or maybe something else? Ryushio is full of stories about creatures that lurk in these waters, and just imagining them sent a chill down my spine.

  I decided to continue on my way, but then I heard a sudden noise coming from the sea. I stopped to look... and there it was: a girl in a sailor uniform emerged from the water.

  I couldn't believe my eyes. Was it my imagination? Or just an eccentric girl who had decided to go for an early swim? I decided not to give it too much thought and not to get too involved, so I turned a blind eye and kept walking.

  When I got to school, I went straight to my classroom and took my usual seat near the back. Just when I thought I might have a normal day, the school principal, Marina Sasaki, burst into the classroom. Although she was young for her position, her presence truly commanded respect.

  “Today is a special day,” she announced, and the murmurs in the classroom immediately died down. “I would like to introduce a new transfer student. Please make her feel welcome and support her in any way she needs.”

  The door opened and all eyes turned toward the entrance.

  There she was: the same girl I had seen on the beach that morning. She entered with boundless energy; her blue hair and perfect uniform made her stand out even more. Immediately, the classroom filled with whispers.

  “Hello, everyone!” she greeted us in a cheerful voice. "I'm Samejima Aoi.

  I'm very excited to be here. I hope to get along well with everyone!"

  Her enthusiasm was so intense that no one knew how to react. The whole room fell silent.

  As she scanned the classroom, her eyes stopped on me and for some reason she smiled at me. At that moment, I froze.

  My instincts told me that this girl was a direct threat to the peaceful life I had managed to build for myself.

  “Okay, Samejima. Let's see where you can sit.”

  While the principal looked for an available seat, Samejima balanced on her tiptoes. It soon became clear that the only empty seat was right next to me.

  “Would you mind sitting there?”

  Oh no.

  Samejima nodded and approached.

  “This place has an incredible view!” she said as she looked out the window.

  Following that, she sat down next to me.

  My heart skipped a beat. I took a deep breath, trying to calm myself.

  Suddenly, she was too close.

  “What's your name?” she asked, leaning a few inches away from me.

  “Hamasaki... Daichi,” I replied with difficulty, still surprised.

  “Daichi... I have a feeling we're going to get along really well!”

  I had no choice but to go with the flow.

  I smiled tensely as the eyes of the classroom were fixed on us. I could feel my efforts to keep a low profile quickly crumbling.

  As the class progressed, I began to notice something strange. Every time she tried to write in her notebook, there was a small crackling sound. The noise repeated itself over and over until I finally decided to look at her desk.

  There I saw a veritable graveyard of broken pencils. It looked like she had been breaking them one after another all morning.

  I froze when I witnessed the scene. Without thinking too much about it, I opened my pencil case and looked for a metal pen I had with me.

  “Samejima-san,” I said, turning to her. “Here. This one is metal; I think it will last a little longer than those pencils... You can keep it.”

  Her eyes lit up when she saw the pen, and she accepted it immediately, as if I had given her a treasure.

  “Oh, thank you so much, Daichi!” she exclaimed, holding it with both hands.

  She stared at the pen I gave her for a long time. It was strange to see how such a simple object could make her so happy.

  “It's just a pen...”

  “No, it's not just that,” she replied, her eyes shining. “It's the first gift a friend has ever given me!”

  For a moment, I didn't know how to respond. Before I could say anything else, the teacher called our attention, and we both quickly returned to our notes.

  Finally, the last class of the day was over, and the students began to pack up their things and leave the classroom. Suddenly, Samejima stood up abruptly and stared at me.

  “Hey, Daichi. Do you want to go to the beach?” she asked.

  “Right... now?”

  Without giving me time to react, she grabbed my arm and started dragging me down the hallway.

  “Wait, my backpack!” I exclaimed, grabbing it just in time.

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  As we ran through the hallways, the laughter and murmurs of our classmates echoed around us. I could feel their curious stares fixed on us, and I couldn't help but feel overwhelmed by the attention we were attracting.

  We left the school and went down the stairs leading to the beach at the foot of the cliff.

  When we finally reached the sand, she let go of my arm and turned to me with a beaming smile.

  “Samejima-san... why did you bring me to the beach?”

  “Wait a minute, okay?” she said, and without further ado, she jumped into the water, still wearing her uniform.

  I couldn't process what had just happened. “Has she gone crazy?” I thought.

  The minutes passed and Samejima didn't come out. I began to imagine the worst. Why isn't she coming out yet? What if something had happened to her?

  Unable to contain myself any longer, I whispered her name.

  “Samejima-san...?”

  There was no answer.

  “Samejima-san!” I shouted.

  My voice echoed across the beach and attracted some curious glances from other students.

  Without thinking, I dropped my backpack and ran toward the water. I waded in as the water rose up my pants and searched desperately for her.

  Suddenly, Samejima emerged from the sea right in front of me. I jumped back, feeling my heart leap out of my chest.

  “I'm back, Daichi!” she said with a mischievous twinkle in her eyes. “What's wrong? Were you worried about me?”

  “You took a long time to come out,” I replied, feeling embarrassed.

  “You don't have to worry,” she winked at me. “I can hold my breath much longer than humans.”

  Did she just say “humans”?

  As I watched her shake the water off herself, I noticed she was holding something in her hands and moved a little closer.

  “What's that?” I asked, pointing to the conch shell she was holding.

  “I'm glad you noticed!” she said, lifting it up to my face. “It's for you, Daichi.”

  She handed it to me without further ado. I held it in my hands, still a little confused.

  “For me? Why are you giving me a conch shell?”

  “It's to thank you for the pen you gave me in class. Besides, this isn't just any conch shell!”

  “Thank you...”

  I examined it carefully, looking for some clue as to what made it special. I had no idea what I was supposed to do with it.

  “Aren't you going to try it?” she insisted, coming dangerously close to me.

  “Try it?”

  Samejima let out a small laugh.

  “Pay attention.”

  She took the conch shell from me and held it with both hands. Then she filled her lungs with a deep breath. And she blew with completely disproportionate force.

  The sound that came out of the conch shell was so powerful that I felt my chest vibrate. I swear even the seagulls flew away in fright and several people around us turned around, startled.

  I was paralyzed.

  “Why did you do that?!” I exclaimed, my heart still racing. “You're going to get us in trouble!”

  “Get us in trouble?” she repeated, tilting her head.

  I didn't understand what was happening, but before I could say anything else, I heard a strange splashing sound coming from the shore. I turned to see what was going on and it took me a second to process it.

  Dozens of fish had gathered, jumping and writhing.

  I took a couple of steps forward, unable to believe what I was seeing.

  “What did you think?” Samejima said, standing next to me with a satisfied expression. “It worked really well, don't you think?”

  “Worked... what?”

  She shrugged.

  "The conch shell! The sound of this conch shell has the power to attract fish. It's like a special whistle to call them. Isn't it great?!“

  As I tried to process the situation, an authoritative voice interrupted the moment.

  ”You two! What are you doing down there?"

  I looked up and there was Principal Sasaki.

  A chill ran down my spine as I imagined the scolding that awaited us. But we hadn't done anything wrong... right?

  Samejima reacted immediately.

  “Run, Daichi!” she shouted.

  Before I could do anything, she grabbed my hand and pulled me with such surprising force that I almost ended up face down on the ground.

  Samejima couldn't stop laughing as she ran.

  I couldn't believe this was happening. I hope we didn't make Principal Sasaki angry...

  When we finally stopped, all I could hear was the frantic rhythm of my breathing. I didn't know how far we had run, but when we stopped, Samejima fell backward onto the sand.

  I stopped a few meters away, bent over at the knees, feeling the exhaustion in every muscle of my body.

  “That was incredible!” she said as she caught her breath.

  I sat down next to her, still panting.

  “Samejima-san... can I ask you something?”

  “Sure, go ahead,” she replied, settling down on the sand.

  I cleared my throat and gathered my courage.

  “This morning... on my way to school, I saw a girl coming out of the sea. That was you, right?”

  She blinked and, for the first time since I'd known her, seemed to be at a loss for words.

  “Huh?” she said, forcing a laugh that clearly gave her away. “No, no... it wasn't me. It must have been your imagination, Daichi.”

  "Also... a moment ago you said you could hold your breath longer than humans. The way you said it sounded like you weren't one yourself.”

  She looked away and started playing with her fingers.

  “That... was just a random comment.”

  “Samejima-san, I want you to tell me the truth.”

  She sighed, as if accepting that there was no way to dodge the question anymore.

  “Waa... am I that obvious?” she muttered. “Okay, I'll tell you the truth.”

  I swallowed hard.

  “Actually... I'm a Demi-human,” she whispered.

  “Really? Do Demi-humans... really exist?”

  Samejima burst out laughing at my disbelief.

  “Of course they do!” she replied with a smile. "Besides, I'm not the only one.

  There are others like me living among humans. We just don't usually tell anyone.“

  ”Are you telling me there are other... Demi-humans here on the island?“ I asked.

  She nodded vigorously.

  ”There should be!“

  It took me a few seconds to process this.

  ”Daichi... there's something else I need to tell you."

  “What is it?”

  Samejima looked out at the sea.

  “I recently moved to this island... but ever since I got here, I've had a strange feeling.”

  “What do you mean?”

  “Hmm...” She tilted her head, searching for the words. “I don't know how to explain it. It's like there's something somewhere underground. Don't you feel it?”

  I shook my head.

  “No... I don't feel anything,” I replied, still trying to understand what she was saying.

  “Really? Maybe it's my demi-human side that allows me to sense it.”

  Then she pointed toward the sea.

  “Besides, it seems I'm not the only one who notices it.”

  I turned to look where she was pointing, and then I noticed it: beneath the surface of the ocean, there were giant shadows moving slowly.

  “W-What are those things?” I asked, frightened.

  Samejima smiled.

  “Don't worry. They're just curious creatures approaching the island. They shouldn't hurt anyone.”

  Even so, my uneasiness didn't go away, and she noticed.

  “Nothing's going to happen, Daichi! Besides, if any of them try anything, I'll take care of them. I'm really strong, you know?”

  I sighed.

  “Okay...”

  I lay down on the sand, looking up at the clear sky, and decided to change the subject.

  “Hey... so, if you're a demi-human... what animal are you?”

  She raised her head with a proud smile, as if she had been waiting for me to ask her that question.

  “Isn't it obvious?” She leaned toward me, and this time, I took a good look. Her fangs were sharp, like little blades. “I'm half-shark!”