Curtain Rising (開幕, Kaimaku) is the fourth chapter of the Hotarubi no Tomoru Koro ni manga.
Teruya, Yue, and Yukito return to find that flies have swarmed the Tadamura house. They go inside and reconvene with Terumi. Meanwhile, Tsunemasa gets separated from Masashi and Nobuteru. Tsunemasa hears a woman's voice in the woods and follows it. He sees a female figure but struggles to get to her as he is repeatedly cut by blade-like leaves. Masashi and Nobuteru find Tsunemasa covered in cuts. On their way back to the house, the trio is assaulted by dogs. Noticing that the flies are gone, the group inside the house helps fend off the dogs. The group is saved by a woman wielding a shotgun.