Just wear the sundress.

You hesitated, fully aware that this is only for a single day, and as much as you may want to, you can't bring yourself to do it. It's your sister, and it just feels wrong. Resolutely, you set her bra and panties aside, biting your lip as you give them one last glance.

You can't help but imagine the sensation—the silk against your skin, the panties snugly embracing your curvy ass, the bra gently brushing against your nipples. Shaking your head, you clear your thoughts and proceed to put on the sundress. Once you're fully dressed, the first thing that strikes you is how **** your lower half feels.

Following your sister's recommendation, you had shaved your entire body, and now you can feel the breeze against your legs. It's a peculiar sensation—a heightened sensitivity that extends to your chest. Not to mention, you're wearing a skirt as well, so the air against your bare ass feels unusual. You haven't mustered the courage to look at yourself in the mirror yet.

Biting your lip, your heart quickens as you slowly turn to face the mirror, revealing the reflection of a cute girl. You stand there for several minutes, trying to process the fact that it's you staring back. Reaching out, you touch the mirror, mirroring the unknown girl's action. Flustered, you start to giggle, realizing the absurdity of your own behavior.

However, the sound of your own giggle causes you to quickly cover your mouth. Why does it sound so feminine? Were you naturally changing your voice without even realizing it?

"I-I um..." You open your mouth, only to hear a more feminine voice escape. Flustered, you promptly close it. Perhaps it's because you're cross-dressing as a girl, wearing makeup, lingerie, and the dress. It all feels strangely natural to you, akin to altering your voice.

You surmise that this moment is the tipping point. Looking at your reflection in the mirror, you undeniably resemble a girl.

Before delving deeper into these thoughts, a knock on your door interrupts you. "Hey, Ash, it's about time to head..." Your sister's sentence trails off as she walks in and gazes at you.

All you can do is nervously fidget with your hands as your face turns red. She exclaims with excitement, rushing over to hug you. "AAAAA! Oh my god, you're so cute! You're going to rock it out there!" she exclaims, beaming.

Then she notices her underwear on your bed and grabs it. "Did you take my underwear?" she asks, sounding shocked. "N-no! You accidentally put it with the dress," you say, trying to defend yourself.

"Oh..." she responds, somewhat disappointed.

Before you can comment on her tone, she compliments you. "Also, you look lovely in that dress," she says. You simply blush and mutter, "T-thanks..." She takes your hand and leads you to her car. "Come on, girl, you're going to be late for school."