''Heheh...''

Ah... my heart was melting. Where could I ever find such an adorable and well-behaved little sister?

I didn't have siblings back on Earth, but I never thought I would want one either, especially after hearing what my friends had to say about theirs. Now, my perception had changed.

I would want to cherish this girl forever.

''Ah, right.''

Before I forgot them again, I reached below my bed and pulled out the elixir I just bought from the auction. Of course, it was properly put in a box and all—my hands still sweated holding such an expensive item.

''Here. Another present for you.'' I whispered, carefully handing the box to Lyra. ''It's an elixir I got. I heard it's good for mana circulation and such.''

Upon opening the box, my little sister's eyes widened. Her mouth hung open for a moment,''...Where did you get this, big sis?''

''Hmm? I picked it up when you were in class a few days ago. Together with the ring, yeah?'' I replied.

''No, but where did you buy this...?''

Expectedly, the sharp Lyra's tone was quite serious. It seemed she had recognized the value of this thing, and halfway through, even Amethyst, who was digging at the snacks, came over to see it for herself.

[This is the real deal...]

The dragon muttered, peeking over her owner's shoulder.

Well, it wasn't like I had anything to confess, so I feigned innocence the whole way through. Fortunately, Lyra trusted me enough not to pursue it further, and I watched as she gulped down the golden liquid in one go.

''How are you feeling?''

''It's the same. Most potions need time to take effect, big sis.''

''Oh, is that right?''

Come on, don't look at me with such suspicious eyes like that?

Either way, this first step could be considered successful. From this point onward, I just needed to feed her potions every now and then, and she'd be good. Later on, when she got into the academy, I could get her the best equipment, too.

Why, I wouldn't ever let my beloved little sister lose to her peers!

----------------------------------------

''Hgn...! Hah...''

Morning had come.

As I stretched my stiff arms from lying asleep like I was dead for a lengthy time, basking in the sunlight, I slowly recalled what had happened.

Yesterday's party ended with the butler, Albert, giving Lyra a gift of his own. When night fell, the two mothers of us also gave some words and small presents, but that didn't really matter.

What mattered the most was that I managed to make my little sister not lonely on her birthday. It was a bit relieving and, at the same time, gloomy to think about this, but when I eventually went away someday, Lyra would probably have many friends who could support her.

This narrative has been unlawfully taken from Royal Road. If you see it on Amazon, please report it.

A little wish of mine was that she would remember me for a long, long time afterward.

''...''

Well, it wasn't good to keep thinking about stuff like this. Let's look for something happier.

...Right. Penelope was going to visit us today. From the tone of her texts, I could tell that she was quite jealous of Rachael the other day. It was a mystery how she found out that I slept with the princess in the first place, but I had to deal with it.

Thankfully, I had already expected this scenario and prepared boxes of condoms beforehand—extra large size, of course.

''Mhm... heheheh...''

What could I even say? She came right when I was a bit frustrated down there. Moreover, I had been anticipating doing it with her for a while. Just what on earth would that pervert do to me?

Ah... not good. I needed to calm down first. The day hadn't even started.

So, I took a few deep breaths and proceeded with my day as usual. I had Mary take care of my appearance first, then ate a bit of breakfast together with Lyra, who seemed quite energetic all of a sudden. It was the same when she picked up the sword as well. It seemed the elixir worked wonderfully.

For lunch, I also ate with Lyra in the shades of our garden. The weather was particularly nice, and looking at my little sister chomping on her food like a hamster greatly motivated me.

And then, as the afternoon rolled out, a black sedan entered our mansion.

''Long time no see, Lady Cecilia.''

''Indeed, Lady Penelope.''

Standing before me was the same classy yet hopeless loser of a woman—Penelope de Bourbon. Perhaps because I hadn't seen her for a while, but she felt a bit... colder today. Or maybe she was sulking. I wasn't sure.

Still, I walked up to Penelope and briefly hugged her.

'''' ... ''''

I could feel her body tensing up, and I'd imagine that our butler and Penelope's attendant, who were with us, were sweating profusely as well. It must have looked like I cheated on Rachael for this.

But she was really warm.

''...Where's your litter sister?'' Penelope asked, fiddling with something in her pocket.

''She's training until six. Shall we wait in the guest room? Or...''

''What are we waiting for, then? Let us move to your room.''

''Ah, of course—''

''I hope you're prepared.''

''...!''

D—Did you have to whisper it to me like that...?

But it was also true that I was weak against these kinds of seduction. Besides, oh, uh, oh, she was indeed angry. I could practically smell the jealousy and annoyance oozing from her eyes.

Knowing that, I obediently let Penelope hold my waist as we headed to my room.

The whole time, there was nothing but silence, yet as if expressing a desperate desire, her grip on me seemed to be unbreakable. When we finally reached our destination and the door shut closed, Penelope familiarly turned the lock and hung her coat on the clothing rack.

I couldn't help but want to comment on it.

'Even Rachael wasn't this used to my room' was probably not a wise thing to say. I had a feeling she would pounce on me viciously if I ever said that.

Still, the atmosphere was tense enough that I felt a bit nervous. As a result, I kept my eyes on her the whole time she made herself comfortable—when she removed her shoes or untied her hair, etc.

''So?''

''Y-Yes?''

The sudden call scared me. Her void-like eyes pierced me, seeming as though they would devour me at any moment. In this regard, she and Lyra were very similar.

But what was more alarming at this point was how Penelope boldly walked toward me before eventually—

''Ah...!''

—pushed me down the bed and laid on top of me. For a while, she planted her face deep in my cleavage, taking in hefty gulps of air without even trying to disguise it. I tried to struggle a bit since it was ticklish, but she was hugging me so tightly that I couldn't move at all.

''Um... Lady Penelope?''

''...''

''Hello...?''

''...How was it?''

Huh? What is she—

''How was the sex with the princess?''

''...!''

Accompanied by a mildly resentful tone, Penelope slowly propped herself up and moved to face me directly, her expression void of delight. At this angle, she looked completely different than usual, with long, loose hair scattering all around me and two annoyed brows—she resembled a beautiful witch.

Yet, I didn't have time to worry about that.

''Too embarrassed to answer?'' Her pink lips parted again. ''Or was it so good you can't describe it with words?''

''U-Um... no, it was... it was g-good, yes...'' I stammered, turning my head sideways. ''And... I was wondering if we could also...''

''...?''

This time, I locked my legs behind her back before reaching for underneath my pillow, and her expression when I blatantly pulled out a box of condoms was absolutely priceless.

''We could also have sex, right...?'' I wryly asked, perhaps hiding my smile behind the pink box.

''Hah. You really are...''