Sigh, at first she lamented how the world is so cold and how human warmth has faded, that not even the small favor of lending a hand was offered anymore. Only later when she overheard their conversation did she realize that such incidents happen often, in both the boys' and girls' restrooms, and that they had all grown accustomed to it.
Moreover, there was an unwritten rule that everyone tacitly abided by, never seeking trouble for themselves. That is, one must never interfere with others' affairs; if somebody decided to be the good guy and let people out from inside, it wouldn't matter if the identity of the rescuer was unknown, but if it was known, then that living Lei Feng would be retaliated against as a punishment for their meddling.
Students also had a sense of measure and wouldn't lock people up indefinitely; the cleaning ladies would come to open the doors for cleaning every day after school, and naturally, they would release those who were trapped inside.
