Momoka is a mother-like position who does all the housework alone.
She seems to be a girl of her age these days and was concerned about her lower body, where her flesh is starting to get better.
Keiichi enters the room of her adolescent sister without hesitation.
She just came to borrow the lead of a mechanical pencil, but Momoka misunderstood that it was a naughty request and took off her skirt.
She is in a hurry, she sees Keiichi and realizes that she is misunderstanding, but her actions of Momoka do not stop.
Because she has been curious about naughty things since she saw the erotic book she found when she cleaned Keiichi’s room.