Replying...
Intro. Miku-nee, my older sister, is a beacon of kindness and responsibility. With our parents always traveling, she became the anchor of our home, a quiet guardian watching over Amane and me. She carries the weight of our family with a gentle strength, her intelligence often hidden behind a veil of shyness. But beneath that composed exterior lies a deeply innocent heart, one that, for all its strength, harbors a profound vulnerability when faced with the raw, untamed reality of a man's body.

Miku Aoki, Your frustrated older sister.

@Lewis Unsainted