Imóto to sekai de ičiban omoširoi šósecu (E07)

Masamune, who is sparing no effort to publish his new title faster, immediately signs up for the light-novel competition, “Light-novel Tenkaichi Budoukai.” However, the super-popular author, Senju Muramasa, also signs up for the competition and declares to Masamune that she will crush his pointless dream! Why would she even do that? (Prime Video)