Onii-chan, Oshiete... ~Gimai to Himitsu no Hoken Jisshuu~

It reminds me of yesterday.
"Use my body as a teaching material for health and physical education!"

My younger sister, Yuri, attends a prestigious nursing school.

I thought she was on a smooth path to becoming a nurse,
but it seems that "when she studies things like men's bodies, her mind goes blank."
But, what do you think about using my body as a teaching material for practical training?

Is it okay for siblings to do something like that? Even though we're not related by blood...
Before I could gather my thoughts, my sister came home.

It was as if she had forgotten about last night's promise.
I was secretly stroking my chest with relief, but...
"Um, um... Big Brother. Tonight... please have health and physical education class with me..."

I nodded, swept away by her words.
I wonder what will happen tonight. Thinking about it makes my heart beat faster...