No matter what was said, Beichuan Si had confirmed Sakurazaka Yuuki's crimes.
In the class roster and group photos of class '09, aside from Ishikawa Kaoru, only her name was listed.
That was why Beichuan Si had given a surprised exclamation, "It really is this person."
From the start, Sakura Yuki's surname was spelled the same as Sakurazaka Yuuki's.
Both their names were pronounced as sakura yuki.
But Beichuan Si had simply been cautious from the beginning—after all, Sakura and Sakurazaka are two different surnames, and since the other party worked within the system, he had no reason to suspect her.
Later on, Beichuan Si even saw what Sakurazaka Yuuki had looked like during her school days.