Upon Taro's return with Rita to the high school block, he was instructed by Mary to accompany her to the twelfth grade to talk some sense to the students. So, Taro had to do so, albeit reluctantly. Once he reached the twelfth grade, he understood that Mary and the teachers' claim about them being extra noisy was kinda true. However, if he were to give out his thoughts, he would probably reply that the echo of the classroom is the reason that their noises were amplified. Of course, their high-pitched voices were the icing on the cake. Taro didn't get why even the boys here have an extra pitch in their voices. He kinda gets why the teachers are advising the kids to talk less; they probably are annoyed by their voices.
Yo, enjoy and cheers!