My sister's secret Rina Koizumi

Rina became a woman inside me from the moment I saw my sister masturbating while muttering "Big brother...". But I died... He can't reach Buddhahood with his feelings for Rina left behind, and he spends his days wandering around his sister, who he can't even touch, while watching her take a bath or watch her have sex with her boyfriend. One day, she gains the power to touch the body and finally succeeds in entering her boyfriend's body!! Rina's younger sister character is a must-see!