Shirakawa Sawahei and Hayakawa Kashi naturally knew that even if they reported it to the police, reopening such an old case would be very difficult.
The recording could not serve as conclusive evidence.
Moreover, strictly speaking, Oga Masato was still a minor, and even if they could convict him, the punishment would unlikely be severe.
Thus, there was only one purpose for the two to report it to the police.
Apply pressure.
Whether to the school or to those two criminals, the involvement of the police was undoubtedly the most terrifying signal. Even if the police were just going through the motions, it would be enough to make the school weigh whether to quickly resolve the matter.
And the quickest way to resolve the matter was to ensure the criminals no longer appeared at the school.