She would have felt bad about violating Narumi-san's trust, especially after all that had happened between them. But Narumi Ayumu had never trusted her to begin with.

She did not feel bad, however, about violating his privacy. She violated everyone's privacy on a routine basis. One did not acquire the enormous knowledge she had through legitimate channels.

She had installed the bug in Ayumu's room the night before she left Japan, on the spur of the moment. She told herself it was a matter of curiosity, a way to know if Ayumu still cared about her. But their final meeting had made the answer to that clear enough; as much as he protested, he truly loved her. There was no doubt.

She installed it because of her bitter regret for doing what had to be done. Yes, it was needed to save the blade children. But her true wish was far more than holding Ayumu's hand. And she installed it because she missed him more than anything in the world. Ayumu couldn't see her. But as long as she could see him, she could blunt the agony of loss and hold out hope for a reunion, once the blade children had been saved.

The woman who had lived as Yuizaki Hiyono had placed the bug so well that it took Ayumu nearly a whole week to notice it. He did not remove it until nearly two years later, when he learned he was to be hospitalized, at which point he disconnected it.

And then Ayumu cried, because it was only the fact that Hiyono was watching that prevented him all this time from being sad.