"Where is this...?"
Sirin entered the Imaginary Space before her. As the Herrscher of the Void, no one understood such things better than she did, so she felt no fear at all.
But after entering the Imaginary Space, she did not find Higokumaru, who had gone in before her. She was the only one here. Still, Sirin was not surprised, because unlike real numbers, of which there was only one kind, there were countless imaginary numbers.
In other words, even if they had entered from the same place, this location contained several Imaginary Spaces. She and Higokumaru... were not in the same Imaginary Space at this moment.
Like the Imaginary Space she controlled, this place was an endless void. Beneath her feet lay bottomless deep water, and it even seemed to be raining around her...
But upon closer inspection, it was not rain at all, but some kind of imaginary lines that could neither be described nor measured.
Such imaginary lines could only exist within Imaginary Space. They could not exist in the real world, because in the real world... the world of real numbers, their existence was impossible.
Sirin swept her gaze over the surroundings but found nothing unusual, a trace of confusion in her eyes. Then, as though recalling something, she hurriedly looked behind her and found that Luna and the others had not followed her in. Behind her was likewise an endless darkness...
Sirin tried using the power of imaginary numbers and found that it was unaffected, which put her at ease. She then continued forward.
However... before Sirin had taken more than a few steps, she suddenly found that the scenery around her had completely changed. She had appeared somewhere deeply familiar.
Looking at what stood before her, Sirin's eyes widened. This was... her childhood home.