The author clarified that relation between difficulty in human-relations and e-mail use of girls' high school students. As a result, there were 19 episodes of difficulty in human-relations related to e-mail use and we could classify them in six types. In addition, we found some episodes of maintained relations and the others broken off. In episodes of maintained relations, there were common territories in the real world, but there were no territories in episodes of relations broken off. Moreover, we found personal spaces in the Internet, and some girls had displeasure in being infringed on their personal spaces.