Real-life version: My older sister, Yoshine Yuria, who is very dignified but makes me ejaculate easily - MIMK-189

[My older sister, though very dignified... has a slightly eccentric personality. We have intense sex every day until we're drenched in sweat!!] My older sister, Higashino Azusa, is both intelligent and beautiful, a source of great pride for me. However, she has a somewhat strange personality. "As a Japanese woman, one must constantly hone oneself!" Every morning, she engages in mysterious training wearing only a pair of trousers, a bizarre habit that surprises everyone. Her enormous breasts sway, her armpits and cleavage are soaked with sweat, radiating a lewd heat that makes anyone's penis erect.