My beloved older cousin becomes my younger brother's sex slave - Satsuki Mei DVRT-005

I have an older cousin, Mei, who is three years older than me. She's always taken care of my brother and me like a real older sister, and I have a soft spot for her... After working for two years, I reunited with her when I returned to my hometown after a long absence. My brother, still like a little kid, kept pestering Mei, wanting to confess his feelings to her this time, but...