Shino also first appears in volume 3, as Mikuni's new shrine maiden. He doesn't speak to anyone, and he's constantly giving rather "strange" looks towards Itsuki. Later, Shino saves Itsuki when a desk almost falls on his head when Itsuki and Mikuni try to medium God, in the process giving himself a head injury. Itsuki carries Shino out of the "shrine of chaos", as all sorts of things flew around, and they ended up in the forest, where Shino kisses him, and speaks for the first time. Later, it is discovered that Shino was "stalking" Itsuki since the ninth grade, and the whole mute thing was part of his plan to intrigue Itsuki. Source: Wikipedia