My Childhood Friend Who is My Girlfriend was Stolen by My Best Friend. From Now on, I'll Flirt with My Ex-Best Friend's Little Sister! - Chapter 3

Mission 1: Make My Childhood Friend Feel Left Out!

The day after I caught my childhood friend cheating on me with my best friend, Monday.

I’m with Rinka-chan, walking side by side on our way to school.

“Just to confirm, senpai, you don’t usually walk to school with that person, right?”

‘That person’ refers to my childhood friend, Tsukimiya Airi.

“Yeah, we used to walk to school together, but ever since I started living alone, we never walk to school together.”

“But what happens if you run into her on the way to school, would you go together with her? If you leave at this time, there’s around 90% chance you’ll run into her, right?”

I live close enough to school that I don’t need to take the train. I just have to avoid being late, so I don’t have a set time to leave home.

Or rather, I tend to leave home really late.

On the other hand, Airi needs to go to school by train. So she usually leaves the house quite early in the morning.

“I think we’ll probably run into her…now that I think about it, whenever I meet Airi that guy is always there with her.”

“Maybe Tsukimiya-san and my brother are already together before you started dating her. My brother used to be really lax about time, but at some point, he started leaving home at a fixed time.”

“…that harsh.”

“I’m sorry. If only I had noticed sooner…”

“Ah, no, it’s not your fault, Rinka-chan.”

The two of them are the ones to blame.

And it’s also partially my fault who can’t see through it.

The atmosphere becomes somewhat heavy.

Suddenly, Rinka-chan clasps her hands together.

“Well, let’s review our mission for today.”

“Mission…well, whatever.”

“First, we will ‘coincidentally’ run into Tsukimiya-san and my brother.”

“Yeah.”

“Naturally, we will walk to school together. While the four of us are walking together, Senpai and I will be chatting just between us. Let’s call it ‘Aren’t those two unusually close with each other? It’s making me uneasy’ Operation!”

“Let’s set the operation name aside…like I said yesterday, is there really any point in doing this?”

“There is! Just showing Tsukimiya-san our cheating scene is not enough. We need to build up evidence first. Otherwise, there’s no basis for the cheating. Plus, we have to warm up first.”

“I see. If we suddenly show her the cheating scene and she doesn’t think it’s cheating, then it all will go to waste.”

“Exactly…do you have any other questions, Private Naegi?”

“I object to my low rank!”

“I’m not accepting objections on that matter. Also, my rank is Sergeant.”

Rinka-chan salutes with a smug expression on her face.

“Ah, hold on…Rinka-chan.”

“Hey, you should call me Sergeant.”

“Shh.”

I put my index finger to my mouth, gesturing for silence.

It seems the time for joking around has already ended. I hide in the shadows nearby.

“Did you find her, Senpai?”

“Yeah, there she is, Airi.”

“But she seems to be alone.”

“Yeah.”

Usually when I see her walking to school, that guy is always beside her.

But this time, she is by herself.

“I wonder if something happened.”

“Who knows? Regardless, our plan doesn’t change, so let’s just go ahead with the plan.”

“Understood.”

Rinka-chan clenches her fists in front of her chest, showing her determination.

I decide to walk a little faster and head towards my childhood friend.

As I casually close the distance between us, I call out to her as if I just spotted her.

“Ah, good morning, Airi!”

Noticing my voice, she turns around.

Her long black hair glistens. A beautiful figure with sharp, defined features.

Tsukimiya Airi, my childhood friend.

Strangely enough, it seems that I still have lingering feelings for her. Just making eye contact with her makes my heart skip a beat.

“Good morning, Toshi-kun. You’re up early today.”

“Yeah, I woke up a bit earlier than usual.”

“Oh, by the way, I sent you a message last night. Why didn’t you respond?”

“Eh, really? …I’m sorry, I didn’t notice.”

“Come on, you need to pay more attention to me. We’re dating, aren’t we?”

I immediately check my smartphone and see there is indeed one unread message from her.

Airi glares at me with a dissatisfied look on her face.

However, she isn’t genuinely angry, as her lips are slightly curled into a smile.

Then, I feel a menacing gaze from behind.

Turning back, I see Rinka-chan glaring at me with an aura of resentment.

“Ah, ahem. Good morning, Tsukimiya-senpai.”

“Good morning. Rin-chan is with you too.”

Rinka-chan clears her throat to draw the attention to herself.

“Well, Senpai insisted going to school with me.”

“Cough, cough!”

She suddenly said so.

Rinka-chan and I are supposed to act as if we had coincidentally met each other and decided to go to school together.

I’m flustered by her unnecessary improv.

“Senpai is surprisingly the type to get lonely, isn’t he? I don’t know how to put it, but it makes me want to be by Senpai’s side and support him.”

“Hmm…I see.”

Airi glares at me.

Why is she looking at me with such a contemptuous gaze?

I pull Rinka-chan aside and whisper softly so that Airi won’t hear what I’m saying.

“This is different from what we have planned. What are you doing?”

“I’m sorry, senpai. The moment I saw that person’s face, I just felt the urge to assert dominance.”

“Assert dominance?”

“Yes. I thought I’d just go ahead and claim you as mine.”

“Keep that feeling in check!”

“Fufu…just thinking about seeing that person’s distorted face makes me drool—”

“Is that really the kind of person you are, Rinka-chan!?”

“You didn’t know that? I’m actually quite a bad person.”

“Well…I knew that.”

“You knew?! You should have denied it! If you don’t deny it, I’ll really seem like a bad person!”

“But you always throw insults at me. Your foul mouth is well-known.”

“I just do that to you, Senpai! I don’t do that to other people!”

“What a terrible special treatment!”

“Well, if I didn’t do that, you wouldn’t pay any attention to me, would you!?”

“That is not the only way for you to get my attention!”

“Anyway, senpai—”

“Ahem!”

While the two of us are whispering to each other, a loud cough interrupts us.

When I turn around, I see Airi with a smile on her face.

However, her eyes are not smiling at all.

“What are you two whispering about? You two seem to be having fun.”

“Ah, no, this is—”

“Did it look that way? Sorry, we didn’t mean anything by it.”

Rinka-chan suddenly interrupted my words and said so.

“Rin-chan, you know that Toshi-kun and I are dating, right?”

“Yes, I know.”

“I’d appreciate it if you could keep it to a reasonable level when getting close to Toshi-kun…ah, I’m not saying you shouldn’t talk to him or anything like that. It’s just—”

Airi moves closer to me and wraps her arm around mine tightly.

“Toshi-kun is mine, okay?”

With that, she made it clear.

Even through the uniform, I can feel her soft touch.

I almost can see blue veins on Rinka-chan’s forehead.

“Oh, really? Then please don’t do anything that would make senpai sad, even if it kills you!”

“Hmm? Yeah, of course. I never want to see Toshi-kun sad.”

…what is she talking about?

My cheeks twist slightly.

No, I shouldn’t show it on my face, but I just can’t bear her words.

She said she never wants to see me sad.

If that’s the case, how could she cheat on me? Does she think I won’t find out about it? Is she that naïve to think that it would be fine as long as I don’t find out about it?

I thought I understand Airi better than anyone else.

But it seems that I was wrong. I can no longer understand what she is thinking.

I shake off Airi’s arm, forcing a smile on my face.

“S-Sorry. I just remembered I have duty today. I’ll go ahead!”

I leave the scene as if running away.

At this rate, I might accidentally say something I shouldn’t.

“Ah, okay then.”

“Senpai…”

I hear Rinka-chan’s voice sounding dejected behind me.

But right now, it’s too difficult for me to turn around.