"Why don't you let my big sister train you, Shingo?" I'm currently living in a semi-cohabitation with my girlfriend, Miu, staying at her place only on weekends. Then one day, her older sister, Yuki-san, suddenly moved in with Miu. Apparently, she's in the middle of "studying" her sex life because of her husband's cheating. Yuki-san works at a personal gym, and at Miu's suggestion, I was half-forced into receiving training from her. With her muscular body and beautiful face right in front of my eyes, my cock becomes rock hard. Noticing my excitement, Yuki-san began to escalate her seductive training...
