He suddenly thought, “If I die, will that blackness go on forever?” That could have been a very scary thing indeed. Eternal blackness with no time nor space. Would he be able to stand it?
Until then, the girl had thought people were all getting bored of the experiment and going home. But with Kei-kun’s disappearance, she realized that was not the case. He had no money; he had to stay here to the end.