[Tsundere to tsundere communication. Tsuyukusa beckons her to follow him and they head outside!! He leads her to... Outside the SUB where there's??? Already a pile of rocks??? These are his throwing rocks I guess.]

You can either see how far you can throw, or just throw it at the side of the building. I think that's better for the softer ones because then sometimes they'll shatter.
[HOW OFTEN DOES HE THROW ROCKS?]