Kana, a high school student, got her first boyfriend. It was her long-time crush, Kisuke-kun. So she absolutely didn't want to fail her first time. She didn't want to be thought of as clumsy. And so Kana used her smelly, dirty grandfather, who was under home care, as a practice tool for sex. Her first kiss, handjob, fellatio, and sex were all with her grandfather. And it was all for Kisuke-kun...