A high school girl gets wet from an unexpected rain shower and boards a crowded train. The man gets excited seeing her wet hair and her see-through bra. Because the train is so crowded, their breasts press against each other, and his penis begins to get erect. Realizing that the erection is due to her see-through bra and the close contact, he presses his penis against the high school girl, and her breathing gradually becomes rougher. Then, whether out of apologizing or excitement, he reaches out for the man's penis...