GRMR-188 Human Observation: A meddlesome older sister gives her inexperienced younger brother a lesson in sex education!? What was supposed to be just teaching him how to use protection turns into a thorough lesson in intimacy, and things end up getting carried away.
A high school boy is secretly and carefully checking a condom in his room. It seems he is practicing for his first time. Then his college-aged older sister accidentally walks in! He tries to hide it in a panic, but she notices right away. Worried about her younger brother’s lack of knowledge, his nosy sister decides to teach him how to use a condom. But she doesn’t stop there and begins giving him a more detailed lesson on how to handle a woman’s body as well…
AvMates Insight
GRMR-188 is one of 36 videos featuring Matsumaru Kasumi (松丸香澄).
Her most frequent collaborator is the maker SILK LABO, which produced about 14% of her total works.
For a full list of Matsumaru Kasumi’s works, see the Matsumaru Kasumi JAV playlist .
Video Information
Release Date:2025-09-11
Product Code:GRMR-188