On a packed train, scenes unfold of intense focus on the nipples of busty women estimated to exceed G-cup size. Using fingertips, lips, and special devices, the performers stimulate the nipples relentlessly until climax is reached. The hypersensitive nipples react like clitorises, bringing the women to repeated orgasms with expressions of complete mental breakdown. Some women beg for even more nipple stimulation, promising to meet again as they eagerly throw themselves into the action.