yui, a vocational school student who works part-time cleaning and doesn't talk to people much because she's shy. yui, who has a nice body with g-cup big breasts and a big-assed waist that you can't tell from her clothes. the colleagues at her part-time job and the men at her work, who found out that yui has such big breasts, are taking advantage of the fact that yui is quiet and doesn't seem to refuse, and are forcefully approaching her and playing with her erotic body as they please.
